MIC5258-1.2YM5 - Micrel Semiconductor, Inc.

MIC5258 Micrel, Inc.

April 2006 1 MIC5258

General Description

The MIC5258 is an efﬁcient, precise CMOS voltage regula-

tor with power good output. The MIC5258 offers better than

3% initial accuracy, and constant ground current (typically

100µA)over load .

The MIC5258 also works with low-ESR ceramic capacitors,

reducing the amount of board space necessary for power

applications, critical in hand-held wireless devices.

Key features include current limit, thermal shutdown, a push-

pull output for faster transient response, and an active clamp to

speed up device turnoff. Available in the IttyBitty™ SOT-23-5

package, the MIC5258 is a ﬁxed 1.2V regulator.

Typical Application

1 5

3 4

47k

OUT

Enable

Shutdown

VOUT

MIC5258-x.xBM5

EN (pin 3) may be

connected directly

to IN (pin 1).

VIN

Low-Noise Regulator Application

MIC5258

150mA µCap CMOS LDO Regulator w/Power Good

Features

• Power Good indicator

• Load independent, ultralow ground current: 100µA

• 150mA output current

• Current limiting

• Thermal shutdown

• Tight load and line regulation

• “Zero” off-mode current

• Stability with low-ESR capacitors

• Fast transient response

• TTL-Logic-controlled enable input

Applications

• Processor power-up sequencing

• Laptop, notebook, and palmtop computers

• PCMCIA VCC and VPP regulation/switching

Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

IttyBitty is a trademark of Micrel, Inc.

Typical Application

Part Number Voltage Junction Temp.

Range* Package

Standard Marking Pb-Free Marking

MIC5258-1.2BM5 LN12 MIC5258-1.2YM5 KN12 1.2V –40ºC to +125ºC SOT-23-5

* Other voltages available. Contact Micrel marketing for information.

MIC5258 Micrel, Inc.

MIC5258 2 April 2006

Pin Conﬁguration

OUT

LNxx

4 5

GND

KNxx

MIC5258-x.xBM5/YM5

Pin Description

Pin Number Pin Name Pin Function

1 IN Supply Input

2 GND Ground

3 EN Enable/Shutdown (Input): CMOS compatible input. Logic high = enable;

logic low = shutdown. Do not leave open.

4 PG Power Good Output

5 OUT Regulator Output

MIC5258 Micrel, Inc.

April 2006 3 MIC5258

Electrical Characteristics

VIN = 2.7V, VEN = VIN; IOUT = 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted.

Symbol Parameter Conditions Min Typical Max Units

VO Output Voltage Accuracy IOUT = 100µA –3 3 %

–4 4 %

ΔVLNR Line Regulation VIN = 2.7V to 6V –0.3 0.3 %/V

ΔVLDR Load Regulation IOUT = 0.1mA to 150mA, Note 4 3.5 4 %

IQ Quiescent Current VEN ≤ 0.4V (shutdown) PG = NC 0.45 1 µA

IGND Ground Pin Current, Note 5 IOUT = 0mA; VIN = 6.0V 110 150 µA

IOUT = 150mA; VIN = 6.0V 110 150 µA

PSRR Power Supply Rejection f = 120Hz, COUT = 4.7µF, IOUT = 150mA tbd dB

ILIM Current Limit VOUT = 0V 160 350 mA

Enable Input

VIL Enable Input Logic-Low Voltage VIN = 5.5V, regulator shutdown 0.4 V

VIH Enable Input Logic-High Voltage VIN = 5.5V, regulator enabled 1.6 V

IEN Enable Input Current VIL ≤ 0.4V; VIN = 5.5V 0.01 µA

VIH ≥ 1.6V; VIN = 5.5V 0.01 µA

Thermal Protection

Thermal Shutdown Temperature 150 °C

Thermal Shutdown Hysteresis 10 °C

Power Good , Note 6

VPG Low Threshold % of VOUT (PG ON) 89 %

High Threshold % of VOUT (PG OFF) 97 %

VOL PG Output Logic-Low Voltage IL = 100µA, fault condition 0.02 0.1 V

IPG Power Good Leakage Current power good off, VPG = 5.5V 0.01 µA

VPG Delay Delay time to Power Good See Timing Diagram 1 5 ms

Note 1. Exceeding the absolute maximum rating may damage the device.

Note 2. The device is not guaranteed to function outside its operating rating.

Note 3. Devices are ESD sensitive. Handling precautions recommended.

Note 4. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load

range from 0.1mA to 150mA. Changes in output voltage due to heating effects are covered by the thermal regulation speciﬁcation.

Note 5. Ground pin current is the regulator quiescent current. The total current drawn from the supply is the sum of the load current plus the ground

pin current.

Note 6. The power good is a function of the output voltage being 5% low and the detection of one of the following: overcurrent, overtemperature or

dropout. See “Applications Information” section for additional information.

Absolute Maximum Ratings (Note 1)

Supply Input Voltage (VIN) ....................................0V to +7V

Enable Input Voltage (VEN) ...................................0V to VIN

Flag Output Voltage (VPG) .....................................0V to VIN

Junction Temperature (TJ) ....................................... +150°C

Storage Temperature ................................ –65°C to +150°C

Lead Temperature (soldering, 5 sec.) ........................ 260°C

ESD, Note 3

Operating Ratings (Note 2)

Input Voltage (VIN) .......................................... +2.7V to +6V

Enable Input Voltage (VEN) ...................................0V to VIN

Flag Output Voltage (VPG) .....................................0V to VIN

Junction Temperature (TJ) ........................ –40°C to +125°C

Thermal Resistance

SOT-23(θJA) .......................................................235°C/W

MIC5258 Micrel, Inc.

MIC5258 4 April 2006

Block Diagram

Reference

Voltage

Quickstart

Under-

voltage

Lockout

Thermal

Sensor

FAULT

GND

ACTIVE SHUTDOWN

PULL

DOWN

Overcurrent

Dropout

Detection

Out of

Regulation

Detection

OUT

Current

Amplifier

Startup/

Shutdown

Control

Error

Amplifier

Delay

1-5ms

Min - Max

97% 97%

89%VOUT

VEN

VPG

Fault Condition

Timing Diagram

MIC5258 Micrel, Inc.

April 2006 5 MIC5258

Typical Characteristics

101

103

105

107

109

111

113

2.5 3 3.5 4 4.5 5 5.5 6 6.5

INPUT VOLTAGE (V)

Ground Current vs.

Input Voltage

IOUT = 100µA

IOUT = 150mA

98.2

98.4

98.6

98.8

99.2

99.4

02 04 06 08 0 100 120 140160

OUTPUT CURRENT (mA)

Ground Current vs.

Output Current

VIN = 3.3V

100

105

110

-40 -20 02 04 06 08 0 100120140

TEMPERATURE (°C)

Ground Current vs.

Temperature

IOUT = 150mA

IOUT = 100µA

260

270

280

290

300

310

320

330

340

350

360

2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1

INPUT VOLTAGE (V)

Short Circuit Current

vs. Input Voltage

200

220

240

260

280

300

320

340

360

380

400

-40 -20 0 20 40 60 80 100120140

UCT

TEMPERATURE(°C)

Short Circuit Current

vs. Temperature

VIN = 3.3V

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

2.0

2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1

INPUT VOLTAGE (V)

Power Good Delay

vs. Input Voltage

IOUT = 100µA

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

2.0

-40 -20 0 20 40 60 80 100120140

TEMPERATURE(°C)

Power Good Delay

vs. Temperature

VIN = 3.3V

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0000

PULL-UP RESISTOR (k Ω)

Power Good Pull-up Resistor

vs. Power Good

P ower Good

P ower F ail

1.170

1.175

1.180

1.185

1.190

1.195

2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1

INPUT VOLTAGE (V)

Output Voltage

vs. Input Voltage

IOUT = 100µA

IOUT = 150mA

1.160

1.165

1.170

1.175

1.180

1.185

1.190

1.195

0 20 40 60 80 100120 140160

OUTPUT CURRENT (mA)

Output Voltage vs.

Output Current

VIN = 3.3V

1.180

1.185

1.190

1.195

1.200

1.205

-40 -20 0 20 40 60 80 100120140

TEMPERATURE(°C)

Output Voltage vs.

Temperature

IOUT = 100µA

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1

INPUT VOLTAGE (V)

Enable Voltage vs.

Input Voltage

IOUT = 100µA

MIC5258 Micrel, Inc.

MIC5258 6 April 2006

0.80

0.85

0.90

0.95

1.00

1.05

1.10

1.15

1.20

-40 -20 0 20 40 60 80 100120140

TEMPERATURE(°C)

Enable Voltage vs.

Temperature

VIN = 3.3V

Power Good Characteristic

TIME (250µs/div)

MIC5258 Micrel, Inc.

April 2006 7 MIC5258

Applications Information

Enable/Shutdown

The MIC5258 comes with an active-high enable pin that al-

lows the regulator to be disabled. Forcing the enable pin low

disables the regulator and sends it into a “zero” off-mode-cur-

rent state. In this state, current consumed by the regulator

goes nearly to zero. Forcing the enable pin high enables

the output voltage. This part is CMOS and the enable pin

cannot be left ﬂoating; a ﬂoating enable pin may cause an

indeterminate state on the output.

Input Capacitor

An input capacitor is not required for stability. A 1µF input

capacitor is recommended when the bulk ac supply capaci-

tance is more than 10 inches away from the device, or when

the supply is a battery.

Output Capacitor

The MIC5258 requires an output capacitor for stability. The

design requires 1µF or greater on the output to maintain stabil-

ity. The capacitor can be a low-ESR ceramic chip capacitor.

The MIC5258 has been designed to work speciﬁcally with

the low-cost, small chip capacitors. Tantalum capacitors can

also be used for improved capacitance over temperature. The

value of the capacitor can be increased without bound.

X7R dielectric ceramic capacitors are recommended because

of their temperature performance. X7R-type capacitors change

capacitance by 15% over their operating temperature range

and are the most stable type of ceramic capacitors. Z5U and

Y5V dielectric capacitors change value by as much 50% and

60% respectively over their operating temperature ranges. To

use a ceramic chip capacitor with Y5V dielectric, the value

must be much higher than an X7R ceramic or a tantalum ca-

pacitor to ensure the same minimum capacitance value over

the operating temperature range. Tantalum capacitors have a

very stable dielectric (10% over their operating temperature

range) and can also be used with this device.

Power Good

The power good output is an open-drain output. It is designed

essentially to work as a power-on reset generator once

the regulated voltage was up and/or a fault condition. The

output of the power good drives low when a fault condition

AND an undervoltage detection occurs. The power good

output comes back up once the output has reached 97% of

its nominal value and a 1ms to 5ms delay has passed. See

Timing Diagram.

The MIC5258’s internal circuit intelligently monitors overcur-

rent, overtemperature and dropout conditions and ORs thes

outputs together ti indicate some fault condition. this output

is fed into an on-board delay circuitry that drives the open

drain transistor to indicate a fault.

Transient Response

The MIC5258 implements a unique output stage to dramati-

cally improve transient response recovery time. The output is

a totem-pole conﬁguration with a P-channel MOSFET pass

device and an N-channel MOSFET clamp. The N-channel

clamp is a signiﬁcantly smaller device that prevents the output

voltage from overshooting when a heavy load is removed.

This feature helps to speed up the transient response by

signiﬁcantly decreasing transient response recovery time

during the transition from heavy load (100mA) to light load

(100µA).

Active Shutdown

The MIC5258 also features an active shutdown clamp, which

is an N-channel MOSFET that turns on when the device is

disabled. This allows the output capacitor and load to dis-

charge, de-energizing the load.

Thermal Considerations

The MIC5258 is designed to provide 150mA of continuous

current in a very small package. Maximum power dissipation

can be calculated based on the output current and the voltage

drop across the part. To determine the maximum power dis-

sipation of the package, use the junction-to-ambient thermal

resistance of the device and the following basic equation:

TJ(max) - TA

(max) = θJA

TJ(max) is the maximum junction temperature of the die, 125°C,

and TA is the ambient operating temperature. θJA is layout

dependent; Table 1 shows examples of junction-to-ambient

thermal resistance for the MIC5258.

Package θJA Recommended θJA 1” Square θJC

Minimum Footprint Copper Clad

SOT-23-5 (M5) 235°C/W 185°C/W 145°C/W

Table 1. SOT-23-5 Thermal Resistance

The actual power dissipation of the regulator circuit can be

determined using the equation:

PD = (VIN – VOUT) IOUT + VIN IGND

Substituting PD(max) for PD and solving for the operating

conditions that are critical to the application will give the

maximum operating conditions for the regulator circuit. For

example, when operating the MIC5258-1.2BM5 at 50°C with

a minimum footprint layout, the maximum input voltage for a

set output current can be determined as follows:

125°C - 50°C

235°C/W

(max) =

PD(max) = 315mW

The junction-to-ambient thermal resistance for the minimum

footprint is 235°C/W, from Table 1. The maximum power dis-

sipation must not be exceeded for proper operation. Using

the output voltage of 1.2V and an output current of 150mA,

the maximum input voltage can be determined. Because this

device is CMOS and the ground current is typically 100µA over

the load range, the power dissipation contributed by the ground

current is < 1% and can be ignored for this calculation.

MIC5258 Micrel, Inc.

MIC5258 8 April 2006

315mW = (VIN – 1.2V) 150mA

315mW = VIN ·150mA – 195mW

510mW = VIN·150mA

VIN(max) = 3.4V

Therefore, a 1.2V application at 150mA of output current

can accept a maximum input voltage of 3.4V in a SOT-23-5

package. For a full discussion of heat sinking and thermal

effects on voltage regulators, refer to the Regulator Thermals

section of Micrel’s Designing with Low-Dropout Voltage

Regulators handbook.

Dual-Supply Operation

When used in dual supply systems where the regulator load

is returned to a negative supply, the output voltage must be

diode clamped to ground.

MIC5258 Micrel, Inc.

April 2006 9 MIC5258

Package Information

SOT-23-5 (M)

MICREL INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA

TEL + 1 (408) 944-0800 FAX + 1 (408) 474-1000 WEB http://www.micrel.com

This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is assumed by Micrel for its use.

Micrel reserves the right to change circuitry and speciﬁcations at any time without notiﬁcation to the customer.

Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can

reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into

the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a signiﬁcant injury to the user. A Purchaser’s

use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify

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