DC1818A - Linear Technology

LTM8001

8001fd

For more information www.linear.com/LTM8001

Typical applicaTion

FeaTures DescripTion

36VIN, 5A µModule

Regulator with 5-Output

Configurable LDO Array

The LT M

8001 is a 36VIN, 5A step-down μModule

regu-

lator with a 5-output configurable LDO array. Operating

over an input voltage range of 6V to 36V, the LTM8001

buck regulator supports an output voltage range of 1.2V

to 24V. Following the buck regulator is an array of five

1.1A linear regulators whose outputs may be connected

in parallel to accommodate a wide variety of load combi-

nations. Three of these LDOs are tied to the output of the

buck regulator, while the other two are tied together to

an undedicated input.

The low profile package (3.42mm) enables utilization of

unused space on the bottom of PC boards for high density

point of load regulation. The LTM8001 is packaged in a

thermally enhanced, compact (15mm × 15mm) and low

profile (3.42mm) overmolded ball grid array (BGA) pack-

age suitable for automated assembly by standard surface

mount equipment. The LTM8001 is available with SnPb

(BGA) or RoHS compliant terminal finish.

applicaTions

n Complete Step-Down Switch Mode Power Supply

with Configurable Array of Five LDOs

n Step-Down Switching Power Supply

– Adjustable 10% Accurate Output Current Limit

–Constant-Current, Constant-Voltage Operation

– Wide Input Voltage Range: 6V to 36V

– 1.2V to 24V Output Voltage

n Configurable Output LDO Array

– Five 1.1A Parallelable Outputs

– Outputs Adjustable from 0V to 24V

– Low Output Noise: 90μVRMS (100Hz to 1MHz)

n 15mm × 15mm × 3.42mm Surface Mount

BGA Package

n FPGA, DSP, ASIC and Microprocessor Supplies

n Servers and Storage Devices

n RF Transceivers L, LT , LTC, LTM , µModule, Linear Technology and the Linear logo are registered trademarks of

Linear Technology Corporation. All other trademarks are the property of their respective owners.

Protected by U.S. Patents, including 7199560, 7321203.

5A Output DC/DC µModule Converter

118k

350kHz

VOUT5

SET5

LDO 5

FBO

STEP-DOWN

SWITCHING

REGULATOR

VOUT4

SET4

LDO 4

VOUT3

SET3

BIAS123

BIAS45

COMP

VREF

ILIM

SYNC

LDO 3

19.6k

GND

10µF

VIN45

510k

3.3V

VOUT2

SET2

LDO 2

VOUT1

SET1

1.2V

1.1V

1.5A

0.9V

1.5A

1.8V

VIN0

RUN

VIN

6V TO 36V

VOUT0

LTM8001

LDO 1

45.3k

4.7µF 4.7µF 2.2µF

54.9k 121k

470µF

8001 TA01

100µF

LTM8001

8001fd

For more information www.linear.com/LTM8001

absoluTe MaxiMuM raTings

VIN0 ........................................................................... 40V

VIN45, BIAS45 ...........................................................25V

BIAS123 ....................................................................25V

FB0, RT, COMP, ILIM, VREF .........................................3V

VOUT0-5 .....................................................................25V

RUN, SYNC, SS ...........................................................6V

SET1-5 (Relative to VOUT1-5, Respectively) ............±0.3V

Current Into SET1-5 ............................................. ±10mA

Current Into RUN Pin ............................................100µA

Maximum Junction Temperature (Notes 2, 3) ....... 125°C

Peak Solder Reflow Body Temperature ................. 245°C

Storage Temperature.............................. –55°C to 125°C

(Note 1)

orDer inForMaTion

pin conFiguraTion

A B C D E F

BGA PACKAGE

121 PADS (15mm × 15mm × 3.42mm)

G H J K

SS RUN

FBO

COMP

SYNC

VREF ILIM

SET1

VIN0

BANK 1

VOUT1

VOUT2

VOUT3

TOP VIEW

VOUT4

VOUT5

SET2SET3SET4

GND

BANK 2

SET5

BIAS45

VOUT0

BANK 4

BIAS123

VIN45

BANK 3

TJMAX = 125°C, θJA = 16.1°C/W, θJCbottom = 5.99°C/W, θJCtop = 13.4°C/W, θJB = 4.98°C/W

θ VALUES DETERMINED PER JEDEC 51-9, 51-12

WEIGHT = 1.8 GRAMS

PART NUMBER PAD OR BALL FINISH

PART MARKING* PACKAGE

TYPE

MSL

RATING

TEMPERATURE RANGE

(SEE NOTE 2)DEVICE FINISH CODE

LT M 8001EY#PBF SAC305 (RoHS) LT M 8001Y e1 BGA 3 –40°C to 125°C

LT M 8001IY#PBF SAC305 (RoHS) LT M 8001Y e1 BGA 3 –40°C to 125°C

LT M 8001IY SnPb (63/37) LT M 8001Y e0 BGA 3 –40°C to 125°C

LT M 8001MPY#PBF SAC305 (RoHS) LT M 8001Y e1 BGA 3 –55°C to 125°C

LT M 8001MPY SnPb (63/37) LT M 8001Y e0 BGA 3 –55°C to 125°C

Consult Marketing for parts specified with wider operating temperature

ranges. *Device temperature grade is indicated by a label on the shipping

container. Pad or ball finish code is per IPC/JEDEC J-STD-609.

• Terminal Finish Part Marking:

www.linear.com/leadfree

• Recommended LGA and BGA PCB Assembly and Manufacturing

Procedures:

www.linear.com/umodule/pcbassembly

• LGA and BGA Package and Tray Drawings:

www.linear.com/packaging

LTM8001

8001fd

For more information www.linear.com/LTM8001

elecTrical characTerisTics

The l denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. RUN = 3V unless otherwise noted (Note 3).

PARAMETER CONDITIONS MIN TYP MAX UNITS

Buck Regulator

Minimum VIN0 Input Voltage l6 V

VOUT0 Output DC Voltage 0A < IOUT ≤ 3A, RFB0 Open

0A < IOUT ≤ 3A; RFB0 = 536Ω

1.2

VOUT0 Output DC Current 6V < VIN0 < 36V, VOUT = 3.3V 0 5 A

Quiescent Current Into VIN0 RUN = 0V

No Load

0.1

µA

VOUT0 Line Regulation 6V < VIN0 < 36V, IOUT = 1A ±0.5 %

VOUT0 Load Regulation VIN0 = 24V, 0A < IOUT < 5A ±1.2 %

VOUT0 RMS Voltage Ripple VIN0 = 24V, IOUT = 5A 10 mV

Switching Frequency RT = 39.2k

RT = 200k

1000

200

kHz

Voltage at FB0 Pin l1.15 1.19 1.21 V

Internal FBO Resistor 10 kΩ

RUN Pin Current RUN = 1.45V 5.5 µA

RUN Threshold Voltage (Falling) 1.49 1.61 V

RUN Threshold Voltage (Rising) 1.63 1.75 V

ILIM Control Range 0 1.5 V

ILIM Pin Current 100 nA

ILIM Current Limit Accuracy ILIM = 1.5V

ILIM = 0.75V

5.1

2.5

6.4

3.4

VREF Voltage 0.5mA Load 1.9 2 2.1 V

SS Pin Current 11 µA

SYNC Input Low Threshold fSYNC = 500kHz 0.8 V

SYNC Input High Threshold fSYNC = 500kHz 1.2 V

SYNC Input Current SYNC = 0V

SYNC = 2V

–0.1

0.1

µA

LDO Array

SET1-5 Pin Current BIAS123 = BIAS45 = 2V, SETx = 0V, IOUT1-5 = 1mA

9.85

9.80

10.15

10.20

µA

VOUTx – SETx Offset Voltage BIAS123 = BIAS45 = 2V, SETx = 0V, IOUT1-5 = 1mA

–4

–6.5

6.5

Line Regulation for SET Current 1V < VOUT0 = VIN45 < 22V, IOUTx = 1mA (Note 4) l11 nA

Line Regulation for VOUT1-5 1V < VOUT0 = VIN45 < 22V, IOUTx = 1mA (Note 4) 0.25 mV

Load Regulation for SETx Current IOUT1-5 = 1mA to 1.1A 25 nA

Load Regulation for VOUT1-5 IOUT1-5 = 1mA to 1.1A

Minimum Load Current for VOUT1-5 (Note 4) VOUT0 = VIN45 = BIAS123 = BIAS45 = 10V

VOUT0 = VIN45 = BIAS123 = BIAS45 = 22V

500

µA

BIAS123, BIAS45 Dropout Voltage IOUT1-5 = 100mA

IOUT1-5 = 1.1A

1.2

1.6

VOUT0 to VOUT1-3 and VIN45 to VOUT4-5 Dropout

Voltage

IOUT1-5 = 100mA

IOUT1-5 = 1.1A

100

500

LTM8001

8001fd

For more information www.linear.com/LTM8001

Typical perForMance characTerisTics

Efficiency vs Output Current,

VOUT0 = 2.5V

Efficiency vs Output Current,

VOUT0 = 3.3V

Efficiency vs Output Current,

VOUT0 = 5V

(TA = 25°C unless otherwise noted. Configured per Table 1, where applicable.)

elecTrical characTerisTics

The l denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. RUN = 3V unless otherwise noted (Note 3).

PARAMETER CONDITIONS MIN TYP MAX UNITS

Maximum VOUT0 to VOUT1-3 and VIN45 to

VOUT4-5 Differential Voltage (Note 5)

IOUT1-5 = 310mA

IOUT1-5 = 125mA

BIAS123, BIAS45 Pin Current IOUT1-5 = 100mA

IOUT1-5 = 1.1A

VOUT1-5 Current Limit (Note 5) VOUT1-5 = –0.1V 1.3 A

VOUT1-5 RMS Output Noise VOUT1-5 = 1V, IOUT1-5 = 1.1A, 100Hz to 1MHz 90 µVRMS

Note 1: Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute

Maximum Rating condition for extended periods may affect device

reliability and lifetime.

Note 2: This μModule regulator includes overtemperature protection that

is intended to protect the device during momentary overload conditions.

Junction temperature will exceed 125°C when overtemperature protection

is active. Continuous operation above the specified maximum operating

junction temperature may impair device reliability.

Note 3: The LTM8001E is guaranteed to meet performance specifications

from 0°C to 125°C internal. Specifications over the full –40°C to

125°C internal operating temperature range are assured by design,

characterization and correlation with statistical process controls. The

LTM8001I is guaranteed to meet specifications over the full

–40°C to 125°C internal operating temperature range. The LTM8001MP

is guaranteed to meet specifications over the full –55°C to 125°C internal

operating temperature range. Note that the maximum internal temperature

is determined by specific operating conditions in conjunction with board

layout, the rated package thermal resistance and other environmental

factors.

Note 4: No minimum load is required if the respective linear regulator is

off, such as when VOUT0 = 0V, VIN45 = 0V, BIAS123 = 0V or BIAS45 = 0V.

Note 5: The current limit may decrease to zero at input-to-output

differential voltages greater than 22V. Operation at voltages for VOUT0,

VIN45, BIAS123 and BIAS45 is allowed up to a maximum of 25V as long

as the difference between the linear regulator input and output voltage

is below the specified differential voltage. Line and load regulation

specifications are not applicable when the device is in current limit.

VOUT0 CURRENT (A)

8001 G01

1 2 3 5

EFFICIENCY (%)

VINO = 12V

VINO = 24V

VINO = 36V

VOUT0 CURRENT (A)

8001 G02

1 2 3 5

EFFICIENCY (%)

VINO = 12V

VINO = 24V

VINO = 36V

VOUT0 CURRENT (A)

100

8001 G03

1 2 3 5

EFFICIENCY (%)

VINO = 12V

VINO = 24V

VINO = 36V

LTM8001

8001fd

For more information www.linear.com/LTM8001

Typical perForMance characTerisTics

Efficiency vs Output Current,

VOUT0 = 8V

Efficiency vs Output Current,

VOUT0 = 12V

Efficiency vs Output Current,

VOUT0 = 18V

Efficiency vs Output Current,

VOUT0 = 24V

Input Current vs Output Current,

VOUT0 = 2.5V

Input Current vs Output Current,

VOUT0 = 3.3V

(TA = 25°C unless otherwise noted. Configured per Table 1, where applicable.)

Input Current vs Output Current,

VOUT0 = 5V

Input Current vs Output Current,

VOUT0 = 8V

Input Current vs Output Current,

VOUT0 = 12V

VOUT0 CURRENT (A)

100

8001 G04

1 2 3 5

EFFICIENCY (%)

VINO = 12V

VINO = 24V

VINO = 36V

VOUT0 CURRENT (A)

100

8001 G05

1 2 3 5

EFFICIENCY (%)

VINO = 24V

VINO = 36V

VOUT0 CURRENT (A)

EFFICIENCY (%)

100

8001 G06

75 1235

VINO = 28V

VINO = 36V

VOUT0 CURRENT (A)

EFFICIENCY (%)

100

8001 G07

80 1235

VINO = 28V

VINO = 36V

VOUT0 CURRENT (A)

INPUT CURRENT (A)

0.9

1.2

1.5

8001 G08

0.6

0.3

01235

VINO = 12V

VINO = 24V

VINO = 36V

VOUT0 CURRENT (A)

INPUT CURRENT (A)

0.2

0.6

0.8

1.0

245

1.8

8001 G09

0.4

1 3

1.2

1.4

1.6

VINO = 12V

VINO = 24V

VINO = 36V

VOUT0 CURRENT (A)

INPUT CURRENT (A)

1.5

2.0

2.5

8001 G10

1.0

0.5

01235

VINO = 12V

VINO = 24V

VINO = 36V

VOUT0 CURRENT (A)

INPUT CURRENT (A)

1.5

2.0

2.5

8001 G11

1.0

0.5

01 2 4

3.0

3.5

4.0 VINO = 12V

VINO = 24V

VINO = 36V

VOUT0 CURRENT (A)

2.0

2.5

3.0

8001 G12

1.5

1.0

1 2 3 5

0.5

INPUT CURRENT (A)

VINO = 24V

VINO = 36V

LTM8001

8001fd

For more information www.linear.com/LTM8001

Typical perForMance characTerisTics

Input Current vs Output Current,

VOUT0 = 18V

Input Current vs Output Current,

VOUT0 = 24V

Minimum VIN0 vs Output Current,

VOUT0 = 3.3V and Below

Minimum VIN0 vs Output Current,

VOUT0 = 5V

Minimum VIN0 vs Output Current,

VOUT0 = 8V

Minimum VIN0 vs Output Current,

VOUT0 = 12V

(TA = 25°C unless otherwise noted. Configured per Table 1, where applicable.)

Minimum VIN0 vs Output Current,

VOUT0 = 18V

Minimum VIN0 vs Output Current,

VOUT0 = 24V

Output Voltage vs Output Current,

VOUT0 = 2.5V

VOUT0 CURRENT (A)

INPUT CURRENT (A)

1.5

2.0

2.5

8001 G13

1.0

0.5

01 2 4

3.0

3.5

4.0

VINO = 28V

VINO = 36V

VOUT0 CURRENT (A)

INPUT CURRENT (A)

3.0

4.0

5.0

8001 G14

2.0

1.0

2.5

3.5

4.5

1.5

0.5

01235

VINO = 28V

VINO = 36V

VOUT0 CURRENT (A)

8001 G1

1 2 3 5

MINIMUM VIN0 VOLTAGE (V)

VOUT0 CURRENT (A)

6.75

6.80

8001 G16

6.70

1 2 3 5

6.65

MINIMUM VIN0 VOLTAGE (V)

VOUT0 CURRENT (A)

9.80

9.85

8001 G17

9.75

1 2 3 5

9.70

MINIMUM VIN0 VOLTAGE (V)

VOUT0 CURRENT (A)

13.85

13.90

13.95

8001 G18

13.80

13.75

1 2 3 5

13.70

13.65

MINIMUM VIN0 VOLTAGE (V)

VOUT0 CURRENT (A)

19.69

19.70

19.71

8001 G19

19.68

19.67

1 2 3 5

19.66

19.65

19.64

MINIMUM VIN0 VOLTAGE (V)

VOUT0 CURRENT (A)

MINIMUM VIN0 VOLTAGE (V)

25.70

26.00

26.05

26.10

8001 G20

25.60

25.90

25.80

25.65

25.95

25.55

25.85

25.75

135

LOAD CURRENT (A)

–10

2.0

2.5

3.5

8001 G21

1.5

1.0

–5 0 10

0.5

3.0

OUTPUT VOLTAGE (V)

LTM8001

8001fd

For more information www.linear.com/LTM8001

Typical perForMance characTerisTics

ILIM Voltage vs Maximum IOUT0

Output Current

VIN0 Input Current vs Voltage,

VOUT0 Shorted

Temperature Rise vs VOUT0 Current,

Buck Regulator, VOUT0 = 3.3V

Temperature Rise vs VOUT0 Current,

Buck Regulator, VOUT0 = 5V

Temperature Rise vs VOUT0 Current,

Buck Regulator, VOUT0 = 2.5V

Temperature Rise vs VOUT0 Current,

Buck Regulator, VOUT0 = 8V

(TA = 25°C unless otherwise noted. Configured per Table 1, where applicable.)

Temperature Rise vs VOUT0 Current,

Buck Regulator, VOUT0 = 12V

Temperature Rise vs VOUT0 Current,

Buck Regulator, VOUT0 = 18V

Temperature Rise vs VOUT0 Current,

Buck Regulator, VOUT0 = 24V

ILIM VOLTAGE (V)

–2

–4

–6

–8 0.75 1.25

8001 G22

0.25 0.5 1 1.5

MAXIMUM CURRENT (A)

VIN0 VOLTAGE (V)

VIN0 INPUT CURRENT (mA)

100

200

300

400

600

612 18 24

8001 G23

30 36

500

VOUT0 CURRENT (A)

TEMPERATURE RISE (°C)

1 2 3 4

8001 G24

12VIN

24VIN

36VIN

VOUT0 CURRENT (A)

TEMPERATURE RISE (°C)

1 2 3 4

8001 G25

12VIN

24VIN

36VIN

VOUT0 CURRENT (A)

8001 G26

1 2 3 5

TEMPERATURE RISE (°C)

12VIN

24VIN

36VIN

VOUT0 CURRENT (A)

TEMPERATURE RISE (°C)

8001 G27

01 2 4

12VIN

24VIN

36VIN

VOUT0 CURRENT (A)

TEMPERATURE RISE (°C)

100

8001 G28

01235

24VIN

36VIN

VOUT0 CURRENT (A)

TEMPERATURE RISE (°C)

100

120

1 2 3 4

8001 G29

28VIN

36VIN

VOUT0 CURRENT (A)

TEMPERATURE RISE (°C)

100

8001 G30

01235

36VIN

LTM8001

8001fd

For more information www.linear.com/LTM8001

Typical perForMance characTerisTics

LDO Input-to-Output Dropout

Voltage vs Output Current

LDO VBIAS-to-Output Dropout

Voltage vs Output Current

LDO Current Limit vs Input-to-

Output Differential Voltage

LDO Temperature Rise vs LDO

Output Current (VIN = 24V,

VOUT0 = 12V, 1 LDO Powered)

LDO Temperature Rise vs LDO

Output Current (VIN = 24V,

VOUT0 = 12V, 5 LDOs in Parallel)

(TA = 25°C unless otherwise noted. Configured per Table 1, where applicable.)

LDO Input Voltage Ripple Rejection

(VOUT4 = 2.5V,

VIN45 = VBIAS45 = 4.5V)

LDO Input Voltage Ripple Rejection

(VOUT4 = 2.5V, VBIAS45 = 4.5V,

VIN45 = 3.5V)

OUTPUT CURRENT (mA)

INPUT-TO-OUTPUT DROPOUT VOLTAGE (mV)

150

200

250

600 1000

8001 G31

100

0200 400 800

300

350

400

OUTPUT CURRENT (mA)

BIAS-TO-OUTPUT DROPOUT VOLTAGE (V)

1.40

1.42

1.44

600 1000

8001 G32

1.38

1.36

1.34 200 400 800

1.46

1.48

1.52

1.50

INPUT-TO-OUTPUT DIFFERENTIAL (V)

LDO CURRENT LIMIT (mA)

800

1000

1200

8001 G33

600

400

010 20 30

200

1600

1400

LDO OUTPUT CURRENT (mA)

TEMPERATURE RISE (°C)

120

500 1000

8001 G34

1500

LDO

INPUT-TO-OUTPUT

DIFFERENTIAL

VOLTAGE

100

0.5V

1.6V

2.4V

9.5V

11.9V

TOTAL LDO OUTPUT CURRENT (A)

TEMPERATURE RISE (°C)

120

1234

8001 G35

LDO

INPUT-TO-OUTPUT

DIFFERENTIAL

VOLTAGE

100

0.5V

0.9V

8.7V

11.9V

FREQUENCY (Hz)

RIPPLE REJECTION (dB)

100

8001 G36

0102103104105106

ILOAD = 100mA

ILOAD = 1.1A

FREQUENCY (Hz)

RIPPLE REJECTION (dB)

100

8001 G37

0102103104105106

ILOAD = 100mA

ILOAD = 1.1A

LTM8001

8001fd

For more information www.linear.com/LTM8001

pin FuncTions

VIN0 (Bank 1): The VIN0 bank supplies current to the

LTM8001’s internal regulator and to the internal power

switches. This pin must be locally bypassed with an ex-

ternal, low ESR capacitor; see Table 1 for recommended

values.

GND (Bank 2): Tie these GND pins to a local ground plane

below the LTM8001 and the circuit components. In most

applications, the bulk of the heat flow out of the LTM8001

is through these pads, so the printed circuit design has a

large impact on the thermal performance of the part. See

the PCB Layout and Thermal Considerations sections for

more details. Return the feedback divider (RFB0) to this net.

VIN45 (Bank 3): Input to the LDOs connected to VOUT4 and

VOUT5. It must be locally bypassed with a low ESR capacitor.

VOUT0 (Bank 4): Switching Power Converter Output Pins.

Apply the output filter capacitor and the output load between

these pins and the GND pins. In most cases, an output

capacitance made up of a combination of ceramic and elec-

trolytic capacitors yields the optimal volumetric solution.

BIAS45 (Pin A8): This pin is the supply pin for the control

circuitry of the LDOs connected to VOUT4 and VOUT5. For

the LDOs to regulate, this voltage must be more than

1.2V to 1.6V greater than the output voltage (see Dropout

specifications).

BIAS123 (Pin B8): This pin is the supply pin for the

control circuitry of the LDOs connected to VOUT1-VOUT3.

For the LDOs to regulate, this voltage must be more than

1.2V to 1.6V greater than the output voltage (see Dropout

specifications).

SS (Pin K4): The Soft-Start Pin. Place an external capacitor

to ground to limit the regulated current during start-up

conditions. The soft-start pin has an 11μA charging current.

SYNC (Pin K7): Frequency Synchronization Pin. This pin

allows the switching frequency to be synchronized to

an external clock. The RT resistor should be chosen to

operate the internal clock at 20% slower than the SYNC

pulse frequency. This pin should be grounded when not

in use. Do not leave this pin floating. When laying out the

board, avoid noise coupling to or from the SYNC trace.

See the Switching Frequency Synchronization section in

Applications Information.

VREF (Pin K8): Buffered 2V Reference Capable of 0.5mA

Drive.

RUN (Pin L4): The RUN pin acts as an enable pin and

turns on the internal circuitry. The pin does not have any

pull up or pull down, requiring a voltage bias for normal

part operation. The RUN pin is internally clamped, so it

may be pulled up to a voltage source that is higher than

Typical perForMance characTerisTics

(TA = 25°C unless otherwise noted. Configured per Table 1, where applicable.)

LDO VBIAS Ripple Rejection

(VOUT4 = 2.5V, VBIAS45 = 4.5V,

VIN45 = 3.5V) LDO Output Ripple

FREQUENCY (Hz)

RIPPLE REJECTION (dB)

100

8001 G38

0102103104105106

ILOAD = 100mA

ILOAD = 1.1A

2µs/DIV

VOUT = 1.2V AT 700mA

COUT1 = 22µF

CSET1 = 1nF

VIN = 12V

VOUT0 = 1.8V LOADED TO

A TOTAL CURRENT OF 5A

100MHz BW

8001 G39

1mV/DIV

LTM8001

8001fd

For more information www.linear.com/LTM8001

block DiagraM

CURRENT

MODE

CONTROLLER

2.2µH

10k

0.2µF 2.2µF

VIN0

RUN

COMP

ILIM

VREF

SYNC

RSENSE VOUT0

VOUT1

SET1

INTERNAL

REGULATOR

VIN0

GND RT FB0 BIAS123 BIAS45 VIN45

1.1A LDO

VOUT2

SET2

1.1A LDO

VOUT3

SET3

1.1A LDO

VOUT4

SET4

1.1A LDO

VOUT5

SET5

8001 BD

1.1A LDO

the absolute maximum voltage rating of 6V through a

resistor, provided the pin current does not exceed 100µA.

FB0 (Pin L5): The LTM8001 regulates its FB0 pin to 1.19V.

Connect the adjust resistor from this pin to ground. The

value of RFB0 is given by the equation:

RFBO =

11.9

OUT

–1.19

where RFB0 is in kΩ.

COMP (Pin L6): Compensation Pin. This pin is generally

not used. The LTM8001 is internally compensated, but

some rare situations may arise that require a modifica-

tion to the control loop. This pin connects directly to the

input PWM comparator of the LTM8001. In most cases,

no adjustment is necessary. If this function is not used,

leave this pin open.

RT (Pin L7): The RT pin is used to program the switch-

ing frequency of the LTM8001 by connecting a resistor

from this pin to ground. The Applications Information

section of the data sheet includes a table to determine the

recommended resistance value and switching frequency.

When using the SYNC function, set the frequency to be

20% lower than the SYNC pulse frequency. Do not leave

this pin open.

ILIM (Pin L8): The ILIM pin reduces the maximum regulated

output current of the LTM8001. The maximum control volt-

age range is 1.5V. ILIM voltages above 1.5V have little or

no effect. If this function is not used, tie this pin to VREF.

SET1, SET2, SET3, SET4, SET5 (Pins L9, H11, G11, D11,

A9): These pins set the regulation point for each LDO. A

fixed current of 10μA flows out of this pin through a single

external resistor, which programs the output voltage of

the device. Output voltage range is zero to the absolute

maximum rated output voltage. The transient performance

can be improved by adding a small capacitor from the

SET pin to ground.

VOUT1 (Pins L10, L11), VOUT2 (Pins J11, K11), VOUT3 (Pins

E11, F11), VOUT4 (Pins B11, C11), VOUT5 (Pins A10, A11):

These are the power outputs of the individual LDOs. There

must be a minimum load current of 1mA or the output may

not regulate. The internal LDOs are rated for positive volt-

ages between their inputs and outputs. Avoid applications

where the internal LDOs can experience a negative voltage,

even during start-up and turn-off transients

pin FuncTions

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operaTion

The LTM8001 consists of two major parts: the first is a

standalone nonisolated step-down switching DC/DC power

converter that can deliver up to 5A of output current. The

second part is an array of five parallelable 1.1A LDOs. The

DC/DC converter provides a precisely regulated output

voltage programmable via one external resistor from 1.2V

to 24V. The input voltage range is 6V to 36V. Given that it

is a step-down converter, make sure that the input volt-

age is high enough to support the desired output voltage

and load current. The linear regulator array consists of

five low drop-out regulators, of which three inputs are

dedicated to the buck converter’s output (VOUT0) and two

tie to an undedicated input (VIN45). Each individual linear

regulator may be set to a unique voltage through its SET

pin, or may be paralleled with other LDOs by tying their

respective SET and VOUT pins together.

The LTM8001 step-down switching converter utilizes fixed

frequency, average current mode control to accurately

regulate the output current. This results in a constant-

voltage, constant-current output characteristic, making

the LTM8001’s step-down regulator well suited for many

supercapacitor and battery charging applications. As shown

in the Typical Performance Characteristics, the current limit

works in both directions. The control loop will regulate the

current in the internal inductor. Once the VOUT0 output has

reached the regulation voltage determined by the resistor

from the FBO pin to ground, the voltage regulation loop will

reduce the output current and maintain the output voltage.

The ILIM input may be used to set the maximum allowable

current output of the LTM8001. The analog control range

of the ILIM pin is from 0V to 1.5V. If the ILIM pin is raised

above 1.5V, there is little or no effect.

The RUN pin functions as a precision enable for the step-

down switching converter connected to VOUT0. If all VOUT1-3

LDO inputs including BIAS are tied to VOUT0, the RUN pin

will also implicitly enable or disable these LDOs as well. If

an external power source is applied to BIAS123 alone or

in combination with VOUT0, RUN will not disable VOUT1-3.

Refer to the Applications Information section Shorted

Input Protection if VOUT0 is forced above VIN0. When the

voltage at the RUN pin is lower than 1.55V, switching is

terminated. Below the turn-on threshold, the RUN pin sinks

5.5μA. This current can be used with a resistor between

RUN and VIN0 to set hysteresis. Please refer to the UVLO

and Shutdown section in the Applications Information

for further details. During start-up, the SS pin is held low

until the part is enabled, after which the capacitor at the

soft-start pin is charged with an 11μA current source.

The LTM8001 is equipped with thermal shutdown circuitry

to protect the device during momentary overload condi-

tions. It is set above the 125°C absolute maximum internal

temperature rating to avoid interfering with normal speci-

fied operation, so internal device temperatures will exceed

the absolute maximum rating when the overtemperature

protection is active. Thus, continuous or repeated activa-

tion of the thermal shutdown may impair device reliability.

During thermal shutdown, all switching is terminated and

the SS pin is driven low.

The switching frequency is determined by a resistor at

the RT pin. The LTM8001 may also be synchronized to

an external clock through the use of the SYNC pin. Please

see the Switching Frequency Synchronization section in

the Applications Information for further details.

The VOUT1-5 linear regulators are easy to use and have

all the protection features expected in high performance

regulators. Included are short-circuit protection and safe

operating area protection, as well as thermal shutdown.

These linear regulators are especially well suited to ap-

plications needing multiple rails. Their architecture allows

their outputs to be adjusted down to zero volts. The output

voltage is set by a single resistor, handling modern low

voltage digital ICs as well as allowing easy parallel opera-

tion and simplified thermal management.

The linear regulators can be operated in two modes. One

mode has the BIAS123 and BIAS45 pins connected to the

linear regulator power input pins (VOUT0 and VIN45) which

gives a limitation of about 1.6V dropout. In the other mode,

the BIAS123 and BIAS45 pins can be tied to a voltage at

least 1.6V above their highest respective outputs. The linear

regulator power input (VOUT0 and VIN45) can then be set

to a lower voltage that meets the dropout requirement,

minimizing the power dissipation.

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applicaTions inForMaTion

For most applications, the design process is straight

forward, summarized as follows:

1. Look at Table 1 and find the row that has the desired

input range and VOUT0 output voltage.

2. Apply the recommended CIN0, COUT0, RFB0 and RT val-

ues. Note that ceramic and electrolytic capacitors are

recommended. These are intended to work in concert

to optimize performance and solution size; apply both

capacitors.

3. Apply the set resistors for the VOUT1, VOUT2, VOUT3,

VOUT4 and VOUT5 regulators. To set the voltage of each

linear regulator, use the equation

RSETX =

OUTX

10µA

where the value of RSET is in Ohms. Note that there is

no minimum positive output voltage for the regulator,

but a minimum load current is required to maintain

regulation regardless of output voltage, (please see

Electrical Characteristics table). For true zero voltage

output operation, this minimum load current must be

returned to a negative supply voltage. If paralleling the

linear regulators, set the output of each regulator to

the same voltage by tying the SETx pins together and

applying a single resistor. The value of the single set

resistor is given by the equation:

SET =

OUT

10µA •n

where n is the number of regulators paralleled.

4. Apply the output capacitors for the VOUT1, VOUT2, VOUT3,

VOUT4 and VOUT5 regulators. A minimum output capaci-

tor of 2.2μF with an ESR of 0.5Ω or less is recommended

to prevent oscillations.

While these component combinations have been tested for

proper operation, it is incumbent upon the user to verify

proper operation over the intended system’s line, load and

environmental conditions. Bear in mind that the maximum

output current is limited by junction temperature, the rela-

tionship between the input and output voltage magnitude

and other factors. Please refer to the graphs in the Typical

Performance Characteristics section for guidance.

The maximum frequency (and attendant RT value) at

which the LTM8001 should be allowed to switch is given

in Table 1 in the fMAX column, while the recommended

frequency (and RT value) for optimal efficiency over the

given input condition is given in the fOPTIMAL column.

There are additional conditions that must be satisfied if

the synchronization function is used. Please refer to the

Switching Frequency Synchronization section for details.

Capacitor Selection Considerations

The CIN and COUT capacitor values in Table 1 are the

minimum recommended values for the associated oper-

ating conditions. Applying capacitor values below those

indicated in Table 1 is not recommended, and may result

in undesirable operation. Using larger values is generally

acceptable, and can yield improved dynamic response, if

necessary. Again, it is incumbent upon the user to verify

proper operation over the intended system’s line, load and

environmental conditions.

Ceramic capacitors are small, robust and have very low ESR.

However, not all ceramic capacitors are suitable. X5R and

X7R types are stable over temperature, applied voltage and

give dependable service. Other types, including Y5V and

Z5U have very large temperature and voltage coefficients

of capacitance. In an application circuit they may have

only a small fraction of their nominal capacitance result-

ing in much higher output voltage ripple than expected.

Many of the output capacitances given in Table 1 specify

an electrolytic capacitor. Ceramic capacitors may also be

used in the application, but it may be necessary to use

more of them. Many high value ceramic capacitors have a

large voltage coefficient, so the actual capacitance of the

component at the desired operating voltage may be only

a fraction of the specified value. Also, the very low ESR of

ceramic capacitors may necessitate additional capacitors

for acceptable stability margin.

A final precaution regarding ceramic capacitors concerns

the maximum input voltage rating of the LTM8001. A

ceramic input capacitor combined with trace or cable

inductance forms a high Q (under damped) tank circuit.

If the LTM8001 circuit is plugged into a live supply, the

input voltage can ring to twice its nominal value, possi-

bly exceeding the device’s rating. This situation is easily

avoided; see the Hot Plugging Safely section.

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LTM8001 Table 1: Recommended Component Values and Configuration for VOUT0 (TA = 25°C)

VIN0 VOUT0 CIN0 COUT0 (CERAMIC) COUT0 (ELECTROLYTIC) RFB0 fOPTIMAL RT(OPTIMAL) fMAX RT(MIN)

6V to 36V 1.2V 10µF, 50V, 1210 100µF, 6.3V, 1210 470µF, 6.3V, 9mΩ, Chemi-Con,

APXF6R3ARA471MH80G

Open 200kHz 200k 250kHz 169k

6V to 36V 1.5V 10µF, 50V, 1210 100µF, 6.3V, 1210 470µF, 6.3V, 9mΩ, Chemi-Con,

APXF6R3ARA471MH80G

38.3k 300kHz 140k 350kHz 118k

6V to 36V 1.8V 10µF, 50V, 1210 100µF, 6.3V, 1210 470µF, 6.3V, 9mΩ, Chemi-Con,

APXF6R3ARA471MH80G

19.6k 350kHz 118k 400kHz 102k

6V to 36V 2.5V 10µF, 50V, 1210 100µF, 6.3V, 1210 330µF, 4V, 27mΩ, OS-CON, 4SVPC330M 9.09k 450kHz 90.9k 525kHz 78.7k

6V to 36V 3.3V 10µF, 50V, 1210 100µF, 6.3V, 1210 330µF, 4V, 27mΩ, OS-CON, 4SVPC330M 5.62k 550kHz 75.0k 625kHz 64.9k

7V to 36V 5V 10µF, 50V, 1210 100µF, 6.3V, 1210 120µF, 16V, 27mΩ, OS-CON,

16SVPC120M

3.09k 600kHz 68.1k 700kHz 57.6k

10V to 36V 8V 10µF, 50V, 1210 100µF, 10V, 1210 120µF, 16V, 27mΩ, OS-CON,

16SVPC120M

1.74k 625kHz 64.9k 750kHz 53.6k

15V to 36V 12V 10µF, 50V, 1210 47µF, 16V, 1210 120µF, 16V, 27mΩ, OS-CON,

16SVPC120M

1.10k 650kHz 61.9k 800kHz 49.9k

22V to 36V 18V 10µF, 50V, 1210 22µF, 25V, 1210 47µF, 20V, 45mΩ, OS-CON, 20SVPS47M 715Ω 675kHz 59.0k 900kHz 44.2k

28V to 36V 24V 4.7µF, 50V,

1210

10µF, 50V, 1206 47µF, 35V, 30mΩ, OS-CON, 35SVPC47M 523Ω 700kHz 57.6k 1MHz 39.2k

9V to 15V 1.2V 10µF, 50V, 1210 100µF, 6.3V, 1210 470µF, 6.3V, 9mΩ, Chemi-Con,

APXF6R3ARA471MH80G

Open 200kHz 200k 525kHz 78.7k

9V to 15V 1.5V 10µF, 50V, 1210 100µF, 6.3V, 1210 470µF, 6.3V, 9mΩ, Chemi-Con,

APXF6R3ARA471MH80G

38.3k 300kHz 140k 650kHz 61.9k

9V to 15V 1.8V 10µF, 50V, 1210 100µF, 6.3V, 1210 470µF, 6.3V, 9mΩ, Chemi-Con,

APXF6R3ARA471MH80G

19.6k 350kHz 118k 800kHz 49.9k

9V to 15V 2.5V 10µF, 50V, 1210 100µF, 6.3V, 1210 330µF, 4V, 27mΩ, OS-CON, 4SVPC330M 9.09k 450kHz 90.9k 1MHz 39.2k

9V to 15V 3.3V 10µF, 50V, 1210 100µF, 6.3V, 1210 330µF, 4V, 27mΩ, OS-CON, 4SVPC330M 5.62k 550kHz 75.0k 1MHz 39.2k

9V to 15V 5V 10µF, 50V, 1210 100µF, 6.3V, 1210 120µF, 16V, 27mΩ, OS-CON,

16SVPC120M

3.09k 600kHz 68.1k 1MHz 39.2k

10V to 15V 8V 10µF, 50V, 1210 100µF, 10V, 1210 120µF, 16V, 27mΩ, OS-CON,

16SVPC120M

1.74k 625kHz 64.9k 1MHz 39.2k

18V to 36V 1.2V 10µF, 50V, 1210 100µF, 6.3V, 1210 470µF, 6.3V, 9mΩ, Chemi-Con,

APXF6R3ARA471MH80G

Open 200kHz 200k 250kHz 169k

18V to 36V 1.5V 10µF, 50V, 1210 100µF, 6.3V, 1210 470µF, 6.3V, 9mΩ, Chemi-Con,

APXF6R3ARA471MH80G

38.3k 300kHz 140k 350kHz 118k

18V to 36V 1.8V 10µF, 50V, 1210 100µF, 6.3V, 1210 470µF, 6.3V, 9mΩ, Chemi-Con,

APXF6R3ARA471MH80G

19.6k 350kHz 118k 400kHz 102k

18V to 36V 2.5V 10µF, 50V, 1210 100µF, 6.3V, 1210 330µF, 4V, 27mΩ, OS-CON, 4SVPC330M 9.09k 450kHz 90.9k 525kHz 78.7k

18V to 36V 3.3 10µF, 50V, 1210 100µF, 6.3V, 1210 330µF, 4V, 27mΩ, OS-CON, 4SVPC330M 5.62k 550kHz 75.0k 625kHz 64.9k

18V to 36V 5V 10µF, 50V, 1210 100µF, 6.3V, 1210 120µF, 16V, 27mΩ, OS-CON,

16SVPC120M

3.09k 600kHz 68.1k 700kHz 57.6k

18V to 36V 8V 10µF, 50V, 1210 100µF, 10V, 1210 120µF, 16V, 27mΩ, OS-CON,

16SVPC120M

1.74k 625kHz 64.9k 750kHz 53.6k

18V to 36V 12V 10µF, 50V, 1210 47µF, 16V, 1210 120µF, 16V, 27mΩ, OS-CON,

16SVPC120M

1.10k 650kHz 61.9k 800kHz 49.9k

Note: An input bulk capacitor is required.

LTM8001

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applicaTions inForMaTion

Programming Switching Frequency

The LTM8001 has an operational switching frequency

range between 200kHz and 1MHz. This frequency is

programmed with an external resistor from the RT pin to

ground. Do not leave this pin open under any condition.

See Table 2 for resistor values and the corresponding

switching frequencies.

Table 2. RT Resistor Values and Their Resultant Switching

Frequencies

SWITCHING FREQUENCY (MHz) RT (kΩ)

1 39.2

0.75 53.6

0.5 82.5

0.3 140

0.2 200

Switching Frequency Trade-Offs

It is recommended that the user apply the optimal RT resis-

tor value given in Table 1 for the input and output operating

condition. System level or other considerations, however,

may necessitate another operating frequency. While the

LTM8001 is flexible enough to accommodate a wide range

of operating frequencies, a haphazardly chosen one may

result in undesirable operation under certain operating or

fault conditions. A frequency that is too high can reduce

efficiency, generate excessive heat or even damage the

LTM8001 in some fault conditions. A frequency that is too

low can result in a final design that has too much output

ripple or too large of an output capacitor.

Switching Frequency Synchronization

The nominal switching frequency of the LTM8001 is

determined by the resistor from the RT pin to GND and

may be set from 200kHz to 1MHz. The internal oscillator

may also be synchronized to an external clock through

the SYNC pin. The external clock applied to the SYNC pin

must have a logic low below 0.8V and a logic high greater

than 1.2V. The input frequency must be 20% higher than

the frequency determined by the resistor at the RT pin.

The SYNC pin must be tied to GND if the synchroniza-

tion to an external clock is not required. When SYNC is

grounded, the switching frequency is determined by the

resistor at the RT pin.

Soft-Start

The soft-start function controls the slew rate of the power

supply output VOUT0 voltage during start-up. A controlled

output voltage ramp minimizes output voltage overshoot,

reduces inrush current from the VIN0 supply, and facili-

tates supply sequencing. A capacitor connected from the

SS pin to GND programs the slew rate. The capacitor is

charged from an internal 11μA current source to produce

a ramped output voltage.

Maximum Output Current Adjust

The LTM8001 features an adjustable accurate current

limit. To adjust the load current limit, an analog voltage

is applied to the ILIM pin. Varying the voltage between

0V and 1.5V adjusts the maximum current between the

minimum and the maximum current, 5.6A typical. Above

1.5V, the control voltage has no effect on the regulated

inductor current. Graphs of the output current vs ILIM volt-

ages are given in the Typical Performance Characteristics

section. The LTM8001 provides a 2V reference voltage for

conveniently applying resistive dividers to set the current

limit. The current limit can be set as shown in Figure 1

with the following equation:

IMAX =7.47

R1+R2

A convenient value of R1 may be 10k. In that case,

R2=

10 •I

MAX

7.47 –I

MAX

kΩ

LTM8001

VREF

8001 F01

ILIM

Figure 1. Setting the Output Current Limit, IMAX

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Load Current Derating Using the ILIM Pin

In high current applications, derating the maximum cur-

rent based on operating temperature may prevent damage

to the load. In addition, many applications have thermal

limitations that will require the regulated current to be

reduced based on the load and/or board temperature. To

achieve this, the LTM8001 uses the ILIM pin to reduce

the effective regulated current in the load. While ILIM

programs the regulated current in the load, it may also

be configured to reduce the regulated current. The load/

board temperature derating is programmed using a resistor

divider with a temperature dependant resistance, as shown

in Figure 2. When the board/load temperature rises, the

ILIM voltage will decrease.

Thermal Shutdown

If the part is too hot, the LTM8001 engages its thermal

shutdown, terminates switching and discharges the soft-

start capacitor. When the part has cooled, the part automati-

cally restarts. This thermal shutdown is set to engage at

temperatures above the 125°C absolute maximum internal

operating rating to ensure that it does not interfere with

functionality in the specified operating range. This means

that internal temperatures will exceed the 125°C absolute

maximum rating when the overtemperature protection is

active, possibly impairing the device’s reliability.

UVLO and Shutdown

The LTM8001 VOUT0 step-down regulator has an internal

UVLO that terminates switching, resets all logic, and dis-

charges the soft-start capacitor for input voltages below

4.2V. The LTM8001 also has a precision RUN function

that enables switching when the voltage at the RUN pin

rises to 1.68V and shuts down the LTM8001 when the

RUN pin voltage falls to 1.55V. There is also an internal

current source that provides 5.5μA of pull-down current to

program additional UVLO hysteresis. For RUN rising, the

current source is sinking 5.5µA until RUN = 1.68V, after

which it turns off. For RUN falling, the current source is

off until the RUN = 1.55V, after which it sinks 5.5µA. The

following equations determine the voltage divider resis-

tors for programming the falling UVLO voltage and rising

enable voltage (VENA) as configured in Figure 4.

R2=

ENA

–1.084 UVLO

5.5µA

R1=1.55 R2

UVLO–1.55

applicaTions inForMaTion

LTM8001

VREF

RNTC RX

RVRV

(OPTION A TO D)

8001 F02

ILIM

RNTC

RNTC R

RNTC

Figure 2. Load Current Derating vs

Temperature Using an NTC Resistor

VOUT0 Output Overvoltage Protection

The LTM8001 switching regulator uses the FB0 pin to both

regulate the output voltage and to provide a high speed

overvoltage lockout to avoid high voltage output condi-

tions. If the output voltage exceeds 125% of the regulated

voltage level (1.5V at the FB0 pin), the LTM8001 terminates

switching and shuts down switching for a brief period. The

output voltage at which output overvoltage protection en-

gages must be greater than 1.5V and is set by the equation:

VOUT =1.5V 1+10k

RFB0

⎛

⎝

⎜⎞

⎠

⎟

where RFB0 is shown in Figure 3.

If the output overvoltage protection engages, the LTM8001

will stop switching. If this is due to some external power

source connected to VOUT0, this source will be free to pull

up VOUT0. If the VOUT0 voltage exceeds the VIN0 input, an

internal power diode will clamp the output to a diode drop

above the input.

LTM8001

VOUT

RFB0

8001 F03

FB0

Figure 3. Voltage Regulation and Overvoltage

Protection Feedback Connections

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The RUN pin has an absolute maximum voltage of 6V.

To accommodate the largest range of applications, there

is an internal Zener diode that clamps this pin, so that it

can be pulled up to a voltage higher than 6V through a

resistor that limits the current to less than 100µA. For

applications where the supply range is greater than 4:1,

size R2 greater than 375k.

Input Precautions

The LTM8001 contains a step-down switching regulator

that operates at a user-selectable frequency in forced

continuous mode. Step-down switching regulators that

operate in forced continuous mode are capable of both

sinking and sourcing current to maintain output voltage

regulation

When the LTM8001 is sinking current, it maintains its

output voltage regulation by power conversion, not power

dissipation. This means that the energy provided to the

LTM8001 is in turn delivered to its input power bus.

There must be something on this power bus to accept or

use the energy, or the LTM8001’s input voltage will rise.

Left unchecked, the energy can raise the input voltage

above the absolute maximum voltage rating and damage

the LTM8001.

In many cases, the system load on the LTM8001 input

bus will be sufficient to absorb the energy delivered by the

μModule regulator. The power required by other devices

will consume more than enough to make up for what

the LTM8001 delivers. In cases where the LTM8001 is

the largest or only power converter, this may not be true

and some means may need to be devised to prevent the

LTM8001’s input from rising too high. Figure 5a shows a

passive crowbar circuit that will dissipate energy during

momentary input overvoltage conditions. The breakdown

voltage of the zener diode is chosen in conjunction with

the resistor R to set the circuit’s trip point. The trip point

is typically set well above the maximum VIN voltage under

normal operating conditions. This circuit does not have a

precision threshold, and is subject to both part-to-part and

temperature variations, so it is not suitable for applications

where high accuracy is required or large voltage margins

are not available.

The circuit in Figure 5b also dissipates energy during mo-

mentary overvoltage conditions, but is more precise than

that in Figure 5a. It uses an inexpensive comparator and

the VREF output of the LTM8001 to establish a reference

voltage. The optional hysteresis resistor in the comparator

circuit avoids MOSFET chatter. Figure 5c shows a circuit

that latches on and crowbars the input in an overvoltage

applicaTions inForMaTion

Load Sharing

The VOUT0 step-down switching converter operates in

fixed frequency forced continuous mode, so it is able to

source and sink current. It is therefore not suitable for

load current sharing.

The linear regulators connected to VOUT1-VOUT5 are inter-

nally ballasted and may be paralleled. To do this, simply

tie the VOUTx and SETx terminals together. When the SET

pins of the regulators are tied together, the RSET resistor

is determined by the equation:

RSET =

OUT

n•10µA

where n is the number of linear regulator outputs tied

together.

All paralleled LDOs must be active in order for this equa-

tion to be true, as it is assumed that all paralleled LDOs

are contributing 10µA to a single voltage set resistor. If

any LDO is off or inactive, it will be unable to contribution

its share of the set current and the output voltage will be

lower than expected.

When paralleling LDOs, tie all of the VOUTx and all of the

SETx pins together. Examples are shown in the Typical

Applications section.

LTM8001

VIN

8001 F04

RUN

Figure 4. UVLO Configuration

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event. The SCR latches when the input voltage threshold

is exceeded, so this circuit should be used with a fuse, as

shown, or employ some other method to interrupt current

from the load.

As mentioned, the LTM8001 sinks current by energy

conversion and not dissipation. Thus, no matter what

protection circuit that is used, the amount of power that the

protection circuit must absorb depends upon the amount

of power at the input. For example, if the output voltage is

2.5V and can sink 5A, the input protection circuit should

be designed to absorb at least 7.5W. In Figures 5a and 5b,

let us say that the protection activation threshold is 30V.

Then the circuit must be designed to be able to dissipate

7.5W and accept 7.5W/30V = 250mA.

Figures 5a through 5c are crowbar circuits, which attempt

to prevent the input voltage from rising above some level

by clamping the input to GND through a power device. In

some cases, it is possible to simply turn off the LTM8001

when the input voltage exceeds some threshold. This

is possible when the voltage power source that drives

current into VOUT never exceeds VIN. An example of this

circuit is shown in Figure 5d. When the power source on

the output drives VIN above a predetermined threshold,

the comparator pulls down on the RUN pin and stops

switching in the LTM8001. When this happens, the input

capacitance needs to absorb the energy stored within the

LTM8001’s internal inductor, resulting in an additional

voltage rise. As shown in the Block Diagram, the internal

applicaTions inForMaTion

VIN

ZENER

DIODE

8001 F05a

LTM8001

LOAD

CURRENT

GND

VOUT0

SOURCING

LOAD

VIN

VREF

8001 F05b

LTM8001

LOAD

CURRENT

GND

VOUT0

SOURCING

LOAD

OPTIONAL

HYSTERESIS

RESISTOR

–

VIN

ZENER

DIODE

SCR

8001 F05a

LTM8001

LOAD

CURRENT

GND

VOUT0

FUSE

SOURCING

LOAD

VIN

RUN

8001 F05d

10µF

LTM8001

LOAD

CURRENT

GND

VOUT0

SOURCING

LOAD

EXTERNAL

REFERENCE

VOLTAGE

–

Figure 5a. The MOSFET Q Dissipates Momentary Energy to

GND. The Zener Diode and Resistor Are Chosen to Ensure That

the MOSFET Turns On Above the Maximum VIN Voltage Under

Normal Operation

Figure 5b. The Comparator in This Circuit Activates the Q

MOSFET at a More Precise Voltage Than the One Shown in

Figure 5a. The Reference for the Comparator is Derived from

the VREF Pin of the LTM8001

Figure 5c. The SCR Latches On When the Activation Threshold is

Reached, So a Fuse or Some Other Method of Disconnecting the

Load Should be Used

Figure 5d. This Comparator Circuit Turns Off the LTM8001 if

the Input Rises Above a Predetermined Threshold. When the

LTM8001 Turns Off, the Energy Stored in the Internal Inductor

Will Raise VIN a Small Amount Above the Threshold.

LTM8001

8001fd

For more information www.linear.com/LTM8001

inductor value is 2.2uH. If the LTM8001 negative current

limit is set to 5A, for example, the energy that the input

capacitance must absorb is 1/2 LI2 = 27.5μJ. Suppose

the comparator circuit in Figure 5d is set to pull the RUN

pin down when VTRIP = 15V. The input voltage will rise

according to the capacitor energy equation:

C VIN2– VTRIP2

( )

=27.5µJ

If the total input capacitance is 10μF, the input voltage

will rise to:

27.5µJ=

10µF VIN2–15V2

( )

VIN = 15.2V

PCB Layout

Most of the headaches associated with PCB layout have

been alleviated or even eliminated by the high level of

integration of the LTM8001. The LTM8001 is neverthe-

less a switching power supply, and care must be taken to

minimize EMI and ensure proper operation. Even with the

high level of integration, you may fail to achieve specified

operation with a haphazard or poor layout. See Figure 6

for a suggested layout. Ensure that the grounding and heat

sinking are acceptable. A few rules to keep in mind are:

1. Place the RSETx, RFB0 and RT resistors as close as pos-

sible to their respective pins.

2. Place the CIN0 capacitor as close as possible to the VIN0

and GND connection of the LTM8001.

3. Place the ceramic COUT0 capacitor as close as possible

to the VOUT0 and GND connection of the LTM8001. The

electrolytic COUT0 capacitor may be farther from the

LTM8001. Place the remaining COUTx output capacitors

as close as possible to the VOUTx pins.

4. Place the CIN0 and COUT0 capacitors such that their

ground currents flow directly adjacent or underneath

the LTM8001.

5. Connect all of the GND connections to as large a copper

pour or plane area as possible on the top layer. Avoid

breaking the ground connection between the external

components and the LTM8001.

6. Use vias to connect the GND copper area to the board’s

internal ground planes. Liberally distribute these GND

vias to provide both a good ground connection and

thermal path to the internal planes of the printed circuit

board. Pay attention to the location and density of the

thermal vias in Figure 6. The LTM8001 can benefit from

the heat sinking afforded by vias that connect to internal

GND planes at these locations, due to their proximity

to internal power handling components. The optimum

number of thermal vias depends upon the printed

circuit board design. For example, a board might use

very small via holes. It should employ more thermal

vias than a board that uses larger holes.

applicaTions inForMaTion

Figure 6. Layout Showing Suggested External Components,

GND Plane and Thermal Vias

Hot Plugging Safely

The small size, robustness and low impedance of ceramic

capacitors make them an attractive option for the input

bypass capacitor of LTM8001. However, these capacitors

can cause problems if the LTM8001 is plugged into a live

input supply (see Application Note 88 for a complete dis-

cussion). The low loss ceramic capacitor combined with

stray inductance in series with the power source forms an

underdamped tank circuit, and the voltage at the VIN0 pin

of the LTM8001 can ring to more than twice the nominal

input voltage, possibly exceeding the LTM8001’s rating

VOUT1

VIN0

VREF

SYNC RT

COMP

FBO

SS RUN

ILIM

VOUT2

VOUT3

VOUT4

VOUT5

VIN45

VOUT0

COUT0

COUT5

GND

8001 F06

GND

CIN0

THERMAL VIAS

SET5

SET4 SET3 SET2

SET1

BIAS45

BIAS123

COUT1

COUT2

COUT3

COUT4

GNDGND

LTM8001

8001fd

For more information www.linear.com/LTM8001

and damaging the part. If the input supply is poorly con-

trolled or the user will be plugging the LTM8001 into an

energized supply, the input network should be designed

to prevent this overshoot. This can be accomplished by

installing a small resistor in series to VIN0, but the most

popular method of controlling input voltage overshoot is

to add an electrolytic bulk capacitor to the VIN0 net. This

capacitor’s relatively high equivalent series resistance

damps the circuit and eliminates the voltage overshoot.

The extra capacitor improves low frequency ripple filtering

and can slightly improve the performance of the circuit,

though it may be physically large.

Shorted Input Protection

Care needs to be taken in systems where the VOUT0 out-

put will be held high when the input to the LTM8001 is

absent. If the VIN0 is allowed to float and the RUN pin is

held high (either by a logic signal or because it is tied to

VIN0), then the LTM8001’s internal circuitry will pull its

quiescent current through its internal power switch. This

is fine if your system can tolerate this state. If the RUN pin

is pulled low, the input current will drop to essentially zero.

However, if the VIN0 is grounded while the VOUT0 output is

held high, then parasitic diodes inside the LTM8001 can

pull large currents from the output through the VIN0 pin.

Figure 7 shows a circuit that will run only when the input

voltage is present and that protects against a shorted or

reversed input.

Charging Applications

The LTM8001’s internal switching step-down regula-

tor’s CVCC operation makes it well suited for battery or

supercapacitor charging applications. A schematic of the

LTM8001 charging a supercapacitor and then distribut-

ing power to various loads through the onboard LDOs is

shown in the Typical Applications section. In this applica-

tion, the supercapacitor is charged through the step-down

switching regulator and not the LDOs. Each LDO is rated

for positive and differential voltages between its input

and output, but may experience a negative voltage during

start-up or turn-off transients if its output is connected to

a battery, supercapacitor or energized load. Avoid using

the LTM8001 in applications where the internal LDOs can

experience a negative voltage.

Thermal Considerations

The LTM8001 output current may need to be derated if it

is required to operate in a high ambient temperature. The

amount of current derating is dependent upon the input

voltage, output power and ambient temperature. The

temperature rise curves given in the Typical Performance

Characteristics section can be used as a guide. These curves

were generated by the LTM8001 mounted to a 59cm2

4-layer FR4 printed circuit board. Boards of other sizes

and layer count can exhibit different thermal behavior, so

it is incumbent upon the user to verify proper operation

over the intended system’s line, load and environmental

operating conditions.

For increased accuracy and fidelity to the actual application,

many designers use finite element analysis (FEA) to predict

thermal performance. To that end, the Pin Configuration

of this data sheet typically gives four thermal coefficients:

θJA: Thermal resistance from junction to ambient

θJCbottom: Thermal resistance from junction to the bottom

of the product case

θJCtop: Thermal resistance from junction to top of the

product case

θJB: Thermal resistance from junction to the printed

circuit board

applicaTions inForMaTion

VIN

RUN

VOUT0

GND

8001 F07

LTM8001

VIN VOUT

Figure 7. The Input Diode Prevents a Shorted Input

from Discharging a Backup Battery Tied to the Output.

It Also Protects the Circuit from a Reversed Input. The

LTM8001 Runs Only When the Input is Present

LTM8001

8001fd

For more information www.linear.com/LTM8001

While the meaning of each of these coefficients may seem

to be intuitive, JEDEC has defined each to avoid confusion

and inconsistency. These definitions are given in JESD

51-12, and are quoted or paraphrased below:

θJA is the natural convection junction-to-ambient air

thermal resistance measured in a one cubic foot sealed

enclosure. This environment is sometimes referred to as

“still air” although natural convection causes the air to

move. This value is determined with the part mounted to

a JESD 51-9 defined test board, which does not reflect an

actual application or viable operating condition.

θJCbottom is the junction-to-board thermal resistance with

all of the component power dissipation flowing through the

bottom of the package. In the typical µModule regulator,

the bulk of the heat flows out the bottom of the package,

but there is always heat flow out into the ambient envi-

ronment. As a result, this thermal resistance value may

be useful for comparing packages but the test conditions

don’t generally match the user’s application.

θJCtop is determined with nearly all of the component power

dissipation flowing through the top of the package. As the

electrical connections of the typical µModule regulator are

on the bottom of the package, it is rare for an application

to operate such that most of the heat flows from the junc-

tion to the top of the part. As in the case of θJCbottom, this

value may be useful for comparing packages but the test

conditions don’t generally match the user’s application.

θJB is the junction-to-board thermal resistance where

almost all of the heat flows through the bottom of the

µModule regulator and into the board, and is really the

sum of the θJCbottom and the thermal resistance of the

bottom of the part through the solder joints and through a

portion of the board. The board temperature is measured

a specified distance from the package, using a two sided,

two layer board. This board is described in JESD 51-9.

Given these definitions, it should now be apparent that none

of these thermal coefficients reflects an actual physical

operating condition of a µModule regulator. Thus, none

of them can be individually used to accurately predict the

thermal performance of the product. Likewise, it would

be inappropriate to attempt to use any one coefficient to

correlate to the junction temperature vs load graphs given

in this product’s data sheet. The only appropriate way to

use the coefficients is when running a detailed thermal

analysis, such as FEA, which considers all of the thermal

resistances simultaneously.

A graphical representation of these thermal resistances

is Figure 8. The blue resistances are contained within the

µModule regulator, and the green are outside.

The die temperature of the LTM8001 must be lower than

the maximum rating of 125°C, so care should be taken in

the layout of the circuit to ensure good heat sinking of the

LTM8001. The bulk of the heat flow out of the LTM8001

is through the bottom of the module and the BGA pads

into the printed circuit board. Consequently a poor printed

circuit board design can cause excessive heating, result-

ing in impaired performance or reliability. Please refer to

the PCB Layout section for printed circuit board design

suggestions.

applicaTions inForMaTion

LTM8001

8001fd

For more information www.linear.com/LTM8001

applicaTions inForMaTion

8001 F08

µMODULE DEVICE

JUNCTION-TO-CASE (TOP)

RESISTANCE

JUNCTION-TO-BOARD RESISTANCE

JUNCTION-TO-AMBIENT RESISTANCE (JESD 51-9 DEFINED BOARD)

CASE (TOP)-TO-AMBIENT

RESISTANCE

BOARD-TO-AMBIENT

RESISTANCE

JUNCTION-TO-CASE

(BOTTOM) RESISTANCE

JUNCTION At

CASE (BOTTOM)-TO-BOARD

RESISTANCE

Figure 8. Thermal Resistances Among μModule Device Printed Circuit Board and Ambient Environment

LTM8001

8001fd

For more information www.linear.com/LTM8001

Typical applicaTions

Dual Input, 2.5V 5A DC/DC µModule Converter Using a Single LTM8001

(External 3.3V Turns On Before or Simultaneously with 12V)

82.5k

VOUT5

SET5

LDO 5

FBO

500kHz

STEP-DOWN

SWITCHING

REGULATOR

VOUT4

SET4

LDO 4

VOUT3

SET3

BIAS123

BIAS45

COMP

VREF

ILIM

SYNC

LDO 3

6.65k

GND

10µF

10µF VIN45

510k

VOUT2

SET2

LDO 2

VOUT1

SET1

2.5V

VIN0

RUN

VIN

12V

EXTERNAL

3.3V

VOUT0

LTM8001

LDO 1

22µF

10nF 49.9k

470µF

8001 TA03

100µF

Five Output DC/DC µModule Regulator

68.1k

600kHz

VOUT5

SET5

LDO 5

FBO

STEP-DOWN

SWITCHING

REGULATOR

VOUT4

SET4

LDO 4

VOUT3

SET3

COMP

VREF

ILIM

SYNC

LDO 3

953Ω 1.21M

2.2µF

GND

VIN45

BIAS123BIAS45

510k

10µF

VOUT2

SET2

LDO 2

VOUT1

SET1

12V1

300mA

12V2

300mA

47µF

120µF

12V3

300mA

12V4

300mA

12V5

300mA

VIN0

RUN

VIN

18V TO 36V

VOUT0

(13.5V)

LTM8001

LDO 1

1.21M

2.2µF

1.21M

2.2µF

1.21M

2.2µF

1.21M

8001 TA02

2.2µF

LTM8001

8001fd

For more information www.linear.com/LTM8001

Typical applicaTions

Supercapacitor Charger and Tw o Output Regulator

68.1k 3.09k

VOUT5

SET5

LDO 5

FBO

600kHz

STEP-DOWN

SWITCHING

REGULATOR

VOUT4

SET4

LDO 4

VOUT3

SET3

BIAS123

BIAS45

COMP

VREF

ILIM

SYNC

LDO 3

GND

10µF

VIN45

200k

48.7k

VOUT2

SET2

LDO 2

VOUT1

SET1

2.5V

0.5A

3.3V

VIN0

RUN

VIN

9V TO 15V

VOUT0

LTM8001

LDO 1

4.7µF

124k

10µF

110k

47µF

8001 TA04

1.5F

5V SUPERCAP

PM-5ROV155-R

LTM8001

8001fd

For more information www.linear.com/LTM8001

Use Tw o LTM8001s to Implement a 2.5VOUT 10A DC/DC µModule Converter

Typical applicaTions

82.5k

VOUT5

SET5

LDO 5

FBO

500kHz

STEP-DOWN

SWITCHING

REGULATOR

VOUT4

SET4

LDO 4

VOUT3

SET3

BIAS123

BIAS45

COMP

VREF

ILIM

SYNC

LDO 3

6.65k

GND

10µF

×2

VIN45

510k

VOUT2

SET2

LDO 2

VOUT1

SET1

VIN0

RUN

VIN1

12V

VOUT0

LTM8001

LDO 1

22µF

24.9k

100µF

8001 TA05

470µF

2.5V

10A

82.5k

VOUT5

SET5

LDO 5

FBO

STEP-DOWN

SWITCHING

REGULATOR

VOUT4

SET4

LDO 4

VOUT3

SET3

BIAS123

BIAS45

COMP

VREF

ILIM

SYNC

LDO 3

6.65k

GND

VIN45

VOUT2

SET2

LDO 2

VOUT1

SET1

VIN0

RUN

VOUT0

LTM8001

LDO 1

100µF 470µF

LTM8001

8001fd

For more information www.linear.com/LTM8001

package DescripTion

Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.

PACKAGE TOP VIEW

PIN “A1”

CORNER

aaa Z

DETAIL A

PACKAGE BOTTOM VIEW

SEE NOTES

123891011 4567

PIN 1

BGA Package

121-Lead (15.00mm × 15.00mm × 3.42mm)

(Reference LTC DWG# 05-08-1923 Rev A)

NOTES:

1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994

2. ALL DIMENSIONS ARE IN MILLIMETERS

BALL DESIGNATION PER JESD MS-028 AND JEP95

5. PRIMARY DATUM -Z- IS SEATING PLANE

6. SOLDER BALL COMPOSITION CAN BE 96.5% Sn/3.0% Ag/0.5% Cu

OR Sn Pb EUTECTIC

DETAILS OF PIN #1 IDENTIFIER ARE OPTIONAL,

BUT MUST BE LOCATED WITHIN THE ZONE INDICATED.

THE PIN #1 IDENTIFIER MAY BE EITHER A MOLD OR

MARKED FEATURE

DETAIL A

Øb (121 PLACES)

DETAIL B

SUBSTRATE

ccc Z

DETAIL B

PACKAGE SIDE VIEW

MOLD

CAP

MX YZddd

MZeee

SYMBOL

aaa

bbb

ccc

ddd

eee

MIN

3.22

0.50

2.72

0.60

0.27

2.45

NOM

3.42

0.60

2.82

0.75

0.63

15.00

1.27

12.70

0.32

2.50

MAX

3.62

0.70

2.92

0.90

0.66

0.37

2.55

0.15

0.10

0.20

0.30

0.15

NOTES

DIMENSIONS

TOTAL NUMBER OF BALLS: 121

SUGGESTED PCB LAYOUT

TOP VIEW

0.000

3.810

5.080

3.810

6.350

5.080

6.350

2.540

1.270

2.540

1.270

6.350

5.080

1.270

6.350

5.080

3.810

2.540

1.270

0.3175

3.810

2.540

0.000

// bbb Z

0.635 ±0.025 Ø 121x

LTMXXXXXX

µModule

BGA 121 1112 REV A

TRAY PIN 1

BEVEL PACKAGE IN TRAY LOADING ORIENTATION

COMPONENT

PIN “A1”

7 PACKAGE ROW AND COLUMN LABELING MAY VARY

AMONG µModule PRODUCTS. REVIEW EACH PACKAGE

LAYOUT CAREFULLY

SEE NOTES

LTM8001

8001fd

For more information www.linear.com/LTM8001

package DescripTion

package phoTo

Table 3. LTM8001 Pinout (Sorted by Pin Number)

PIN NAME PIN NAME PIN NAME PIN NAME PIN NAME PIN NAME

A1 GND B1 GND C1 GND D1 GND E1 GND F1 GND

A2 GND B2 GND C2 GND D2 GND E2 GND F2 GND

A3 VOUT0 B3 VOUT0 C3 VOUT0 D3 GND E3 GND F3 GND

A4 VOUT0 B4 VOUT0 C4 VOUT0 D4 GND E4 GND F4 GND

A5 VOUT0 B5 VOUT0 C5 VOUT0 D5 GND E5 GND F5 GND

A6 VIN45 B6 VIN45 C6 VIN45 D6 GND E6 GND F6 GND

A7 VIN45 B7 VIN45 C7 VIN45 D7 GND E7 GND F7 GND

A8 BIAS45 B8 BIAS123 C8 GND D8 GND E8 GND F8 GND

A9 SET5 B9 GND C9 GND D9 GND E9 GND F9 GND

A10 VOUT5 B10 GND C10 GND D10 GND E10 GND F10 GND

A11 VOUT5 B11 VOUT4 C11 VOUT4 D11 SET4 E11 VOUT3 F11 VOUT3

PIN NAME PIN NAME PIN NAME PIN NAME PIN NAME

G1 GND H1 GND J1 VIN0 K1 VIN0 L1 VIN0

G2 GND H2 GND J2 VIN0 K2 VIN0 L2 VIN0

G3 GND H3 GND J3 VIN0 K3 VIN0 L3 VIN0

G4 GND H4 GND J4 GND K4 SS L4 RUN

G5 GND H5 GND J5 GND K5 GND L5 FB0

G6 GND H6 GND J6 GND K6 GND L6 COMP

G7 GND H7 GND J7 GND K7 SYNC L7 RT

G8 GND H8GND J8 GND K8 VREF L8 ILIM

G9 GND H9 GND J9 GND K9 GND L9 SET1

G10 GND H10 GND J10 GND K10 GND L10 VOUT1

G11 SET3 H11 SET2 J11 VOUT2 K11 VOUT2 L11 VOUT1

LTM8001

8001fd

For more information www.linear.com/LTM8001

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-

tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.

revision hisTory

REV DATE DESCRIPTION PAGE NUMBER

A 09/13 Update Features section

Update test conditions and limits

Correct input power pin name

3, 4

B 02/14 Add SnPb BGA package option 1, 2

C 08/14 Add MP-grade option 2, 3

D 08/15 Modified maximum VOUT conditions

Amended VOUT RUN description

LTM8001

8001fd

For more information www.linear.com/LTM8001

 LINEAR TECHNOLOGY CORPORATION 2013

LT 0815 REV D • PRINTED IN USA

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LTM8001

relaTeD parTs

Typical applicaTion

Three Output DC/DC µModule Converter

118k

VOUT5

SET5

LDO 5

FBO

350kHz

STEP-DOWN

SWITCHING

REGULATOR

VOUT4

SET4

LDO 4

VOUT3

SET3

BIAS123

BIAS45

COMP

VREF

ILIM

SYNC

LDO 3

19.6k

GND

10µF

10k

20.5k

VIN45

510k

VOUT2

SET2

LDO 2

VOUT1

SET1

2.2A

1.2V

1.3A

1.8V

VIN0

RUN

VIN

9V TO 18V

VOUT0

LTM8001

LDO 1

60.4k

4.7µF 10µF

33.2k

470µF

8001 TA06

100µF

PART NUMBER DESCRIPTION COMMENTS

LTM8026 36VIN, 5A Step-Down µModule Regulator with

Adjustable Current Limit

6V ≤ VIN ≤ 36V, 1.2V ≤ VOUT ≤ 24V, Adjustable Current Limit, Parallelable

Outputs, CLK Input, 11.25mm × 15mm × 2.82mm LGA

LTM8052 36VIN, ±5A Step-Down µModule Regulator with

Adjustable Current Limit

6V ≤ VIN ≤ 36V, 1.2V ≤ VOUT ≤ 24V, –5V ≤ IOUT ≤ 5A, Adjustable Current

Limit, CLK Input, 11.25mm × 15mm × 2.82mm LGA, Pin Compatible with

LTM8026

LTM8061 32V, 2A Step-Down µModule Battery Charger with

Programmable Input Current Limit

Suitable for CC-CV Charging Single and Dual Cell Li-Ion or Li-Poly Batteries,

4.95V ≤ VIN ≤ 32V, C/10 or Adjustable Timer Charge Termination, NTC

Resistor Monitor Input, 9mm × 15mm × 4.32mm LGA

LTM8062A 32V, 2A Step-Down µModule Battery Charger with

Integrated Maximum Peak Power Tracking (MPPT) for

Solar applications

Suitable for CC-CV Charging Method Battery Chemistries (Li-Ion, Li-Poly,

Lead-Acid, LiFePO4), User Adjustable MPPT Servo Voltage, 4.95V ≤ VIN

≤ 32V, 3.3V ≤ VBATT ≤ 18.8V Adjustable, C/10 or Adjustable Timer Charge

Termination, NTC Resistor Monitor Input, 9mm × 15mm × 4.32mm LGA

LTM8033 36V, 3A EN55022 Class B Certified DC/DC Step-Down

µModule Regulator

3.6V ≤ VIN ≤ 36V, 0.8V ≤ VOUT ≤ 24V, Synchronizable, 11.25mm × 15mm ×

4.32mm LGA

LTM4613 36VIN, 8A EN55022 Class B Certified DC/DC Step-

Down µModule Regulator

5V ≤ VIN ≤ 36V, 3.3V ≤ VOUT ≤ 15V, PLL input, VOUT Tracking and Margining,

15mm × 15mm × 4.32mm LGA

LTM8048 1.5W, 725VDC Galvanically Isolated µModule Converter

with LDO Post regulator

3.1V ≤ VIN ≤ 32V, 2.5V ≤ VOUT ≤ 12V, 1mVP-P Output Ripple, Internal Isolated

Transformer, 9mm × 11.25mm × 4.92mm BGA

LTC2978 Octal Digital Power Supply Manager with EEPROM I2C/PMBus Interface, Configuration EEPROM, Fault Logging, 16-Bit ADC with

±0.25% TUE, 3.3V to 15V Operation

LTC2974 Quad Digital Power Supply Manager with EEPROM I2C/PMBus Interface, Configuration EEPROM, Fault Logging, per Channel

Voltage, Current and Temperature Measurements

LTC3880 Dual Output PolyPhase

Step-Down DC/DC Controller

with Digital Power System Management

I2C/PMBus Interface, Configuration EEPROM, Fault Logging, ±0.5% Output

Voltage Accuracy, MOSFET Gate Drivers