MIC5353
500mA LDO in 1.6mm × 1.6mm Package
ULDO is a trademark of Micrel, Inc
MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
May 2010 M9999-052510
General Description
The MIC5353 is a high-performance, single-output, ultra-
low LDO (ULDO™) regulator, offering a low total output
noise of 30μVRMS. The MIC5353 is capable of sourcing
500mA output current and offers high-PSRR and low-
output noise, making it an ideal solution for RF
applications.
The MIC5353 provides 2% accuracy, extremely low
dropout voltage (160mV @ 500mA), and low ground
current (typically 90µA) making it ideal for battery-operated
applications. When disabled, the MIC5353 enters a zero-
off-mode current state, thereby drawing almost no current.
The MIC5353 is available in the 1.6mm x 1.6mm Thin
MLF® package, occupying only 2.56mm2 of PCB area, a
36% reduction in board area compared to SC-70 and 2mm
x 2mm Thin MLF® packages.
The MIC5353 has an operating junction temperature range
of –40°C to +125°C and is available in fixed and adjustable
output voltages in lead-free (RoHS-compliant) Thin MLF®
package.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
500mA guaranteed output current
Input voltage range: 2.6V to 6V
Ultra low dropout voltage: 160mV @ 500mA
± 2% initial accuracy
Ultra low output noise: 30µVrms
Low quiescent current: 90µA
Stable with ceramic output capacitors
35µs turn-on time
Thermal shutdown and current limit protection
Tiny 6-pin 1.6mm x 1.6mm Thin MLF® leadless package
Applications
Mobile Phones
GPS, PDAs, PMP, handhelds
Portable electronics
Digital still and video cameras
Digital TV
_________________________________________________________________________________________________________________________
Typical Application
Portable Application
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Ordering Information
Part Number Marking Code(1) Output Voltage(2) Temperature Range Package
MIC5353-1.8YMT 18R 1.8V –40°C to +125°C 6-Pin 1.6mm x 1.6mm Thin MLF®
MIC5353-2.5YMT 25R 2.5V –40°C to +125°C 6-Pin 1.6mm x 1.6mm Thin MLF®
MIC5353-2.6YMT 26R 2.6V –40°C to +125°C 6-Pin 1.6mm x 1.6mm Thin MLF®
MIC5353-2.8YMT 28R 2.8V –40°C to +125°C 6-Pin 1.6mm x 1.6mm Thin MLF®
MIC5353-3.0YMT 30R 3.0V –40°C to +125°C 6-Pin 1.6mm x 1.6mm Thin MLF®
MIC5353-3.3YMT 33R 3.3V –40°C to +125°C 6-Pin 1.6mm x 1.6mm Thin MLF®
MIC5353YMT AAR ADJ –40°C to +125°C 6-Pin 1.6mm x 1.6mm Thin MLF®
Notes:
1. Pin 1 identifier= “”.
2. For other voltage options contact Micrel Marketing.
3. Thin MLF® is a GREEN RoHS compliant package. Lead finish is NiPdAu, Mold compound is Halogen Free.
Pin Configuration
6-Pin 1.6mm × 1.6mm Thin MLF® (MT)
Fixed
(TOP VIEW)
6-Pin 1.6mm × 1.6mm Thin MLF®(MT)
Adjustable
(TOP VIEW)
Pin Description
Pin Number
Thin MLF-6
Fixed
Pin Number
Thin MLF-6
Adjustable
Pin Name Pin Function
1 1 EN Enable Input. Active High. High = ON, low = OFF. Do not leave floating.
2 2 GND Ground.
3 3 VIN Supply Input.
4 4 VOUT Output Voltage.
5 NC No connection.
5 ADJ Adjust Input. Connect to external resistor voltage divider network.
6 6 BYP
Reference Bypass: Connect external 0.1μF to GND for reduced Output Noise. May
be left open.
EPad EPad HS PAD Exposed Heat-sink Pad connected to ground internally.
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Absolute Maximum Ratings(1)
Supply Voltage (VIN)..................................... 0.3V to +6.5V
Enable Input Voltage (VEN)................................0.3V to VIN
Power Dissipation ..................................Internally Limited(3)
Lead Temperature (soldering, 3sec)..........................260°C
Storage Temperature (TS).........................65°C to +150°C
ESD Rating(4)................................................................. 2KV
Operating Ratings(2)
Supply Voltage (VIN) ...................................... +2.6V to +6.0V
Enable Input Voltage (VEN) ......................................0V to VIN
Junction Temperature (TJ) .......................... 40°C to +125°C
Junction Thermal Resistance
6-Pin 1.6mm x1.6mm Thin MLF® (θJA) ...........92.4°C/W
Electrical Characteristics(5)
VIN = VOUT + 1.0V; COUT = 1.0µF; IOUT = 100µA; TJ = 25°C, bold values indicate –40°C to +125°C, unless noted.
Parameter Conditions Min. Typ. Max. Units
Variation from nominal VOUT -2.0 +2.0
Output Voltage Accuracy Variation from nominal VOUT; –40°C to +125°C -3.0 +3.0 %
0.05 0.3
Line Regulation VIN = VOUT + 1V to 6V; IOUT = 100µA
0.6 %/V
Load Regulation IOUT = 100µA to 500mA 0.15 2.0 %
IOUT = 150mA 50 100
IOUT = 300mA 100 200
Dropout Voltage (6)
IOUT = 500mA 160 350
mV
Ground Pin Current IOUT = 0 to 500mA 90 175 µA
Ground Pin Current in Shutdown VEN 0.2V 0.01 2 µA
f = 1kHz; COUT = 1.0µF; CBYP = 0.1µF 60 dB
Ripple Rejection f = 20kHz; COUT = 1.0µF; CBYP = 0.1µF 45
Current Limit VOUT = 0V 600 1100 1600 mA
Output Voltage Noise COUT = 1.0µF; CBYP = 0.1µF; 10Hz to 100kHz 30 µVRMS
Enable Input
Logic Low 0.2
Enable Input Voltage Logic High 1.2
V
VIL 0.2V 0.01 1
Enable Input Current VIH 1.2V 0.01 1 µA
Turn-on Time
Turn-on Time COUT = 1.0µF; CBYP = 0.1µF 35 100 µs
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. The maximum allowable power dissipation of any TA (ambient temperature) is PD(max) = (TJ(max) – TA) / θJA. Exceeding the maximum allowable
power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown.
4. Devices are ESD sensitive. Handling precautions recommended. Human body model 1.5K in series with 100pF.
5. Specification for packaged product only.
6. Dropout voltage is defined as the input-to-output differential at which the output voltage drops 2% below its nominal value measured at 1V
differential.
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Functional Diagram
MIC5353 Block Diagram – FIXED
MIC5353 Block Diagram – ADJUSTABLE
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Typical Characteristics
Dropout Voltage
vs. Output Current
0
20
40
60
80
100
120
140
160
180
200
0 50 100 150 200 250 300 350 400 450 500
OUTPUT CURRENT (mA)
DROPOUT VOLTAGE (mV)
Dropout Voltage
vs. Temperature
0
50
100
150
200
250
-40 -20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)
DROPOUT VOLTAGE (mV
)
150mA
500mA
300mA
Ground Current
vs. Output Current
80
82
84
86
88
90
92
0 100 200 300 400 500
Output Current(mA)
Ground Current(μA)
V
OUT
= 2.8V
V
IN
= 3.8V
Ground Current
vs. Temperature
60
70
80
90
100
110
120
-40 -20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)
GROUND CURRENT (μA)
I
OUT
= 500mA
I
OUT
= 100μA
Output Voltage
vs. Output Current
1.76
1.77
1.78
1.79
1.8
1.81
1.82
1.83
1.84
0 50 100 150 200 250 300 350 400 450 500
OUTPUT CURRENT(mA)
OUTPUT VOLTAGE(V)
VIN=2.8V
COUT=CIN=1μF
Current Limit
vs. Input Voltage
0.8
0.9
1
1.1
1.2
1.3
1.4
2.533.544.55 5.56
INPU T VO LT AGE(V)
CURRENT LIMIT(mA)
V
OUT
=2.8V
C
IN
=C
OUT
=1μF
PSRR
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10 100 1,000 10,000 100,000 1,000,000 10,000,000
FREQUENCY (Hz)
dB
100µA
300µA
500µA
C
OUT
= 1µF
C
BYP
= 0.1µF
Output Noise Spectral Density
0.001
0.01
0.1
1
10
10 100 1,000 10,000 100,000 1,000,000 10,000,000
FREQUENCY (Hz)
Noise uV/Hz
VIN = 4.5V
COUT = 1µF
VOUT = 1.8V
ILOA D = 50mA
CBYP = 0.1µF
Output Voltage
vs. Input Voltage
2
2.2
2.4
2.6
2.8
3
3.2
3.4
3.6
2.6 3 3.4 3.8 4.2 4.6 5 5.4 5.8
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
150mA
100μA
300mA
500mA
V
OUT
= 2.8V
C
IN
= C
OUT
= 1μF
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Functional Characteristics
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Applications Information
Enable/Shutdown
The MIC5353 comes with an active-high enable pin that
allows the regulator to be disabled. Forcing the enable
pin low disables the regulator and sends it into a “zero”
off-mode-current state. In this state, current consumed
by the regulator goes nearly to zero. Forcing the enable
pin high enables the output voltage. The active-high
enable pin uses CMOS technology and the enable pin
cannot be left floating; a floating enable pin may cause
an indeterminate state on the output.
Input Capacitor
The MIC5353 is a high-performance, high bandwidth
device. Therefore, it requires a well-bypassed input
supply for optimal performance. A 1µF capacitor is
required from the input-to-ground to provide stability.
Low-ESR ceramic capacitors provide optimal
performance at a minimum of space. The use of
additional high-frequency capacitors, such as small-
valued NPO dielectric-type capacitors, help filter out
high-frequency noise and are good practice in any RF-
based circuit.
Output Capacitor
The MIC5353 requires an output capacitor of 1µF or
greater to maintain stability. The design is optimized for
use with low-ESR ceramic chip capacitors. High-ESR
capacitors may cause high-frequency oscillation. The
output capacitor can be increased, although
performance has been optimized for a 1µF ceramic
output capacitor and doing so does not improve
significantly with larger capacitance.
X7R/X5R dielectric-type ceramic capacitors are
recommended because of their temperature
performance. The 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 as 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 capacitor thereby
ensuring the same minimum capacitance over the
equivalent operating temperature range.
Bypass Capacitor
A capacitor can be placed from the noise bypass pin-to-
ground to reduce output voltage noise. The capacitor
bypasses the internal reference. A 0.1μF capacitor is
recommended for applications that require low-noise
outputs. The bypass capacitor can be increased, further
reducing noise and improving PSRR. Turn-on time
increases slightly with respect to bypass capacitance.
A unique, quick-start circuit allows the MIC5353 to drive
a large capacitor on the bypass pin without significantly
slowing turn-on time.
No-Load Stability
Unlike many other voltage regulators, the MIC5353 will
remain stable and in regulation with no load. This is
especially important in CMOS RAM keep-alive
applications.
Adjustable Regulator Application
Adjustable regulators use the ratio of two resistors to
multiply the reference voltage to produce the desired
output voltage. The MIC5353 can be adjusted from
1.25V to 5.5V by using two external resistors (Figure 1).
The resistors set the output voltage based on the
following equation:
+= R2
R1
1VV REFOUT
V
REF = 1.25V
Figure 1. Adjustable Voltage Output
Thermal Considerations
The MIC5353 is designed to provide 500mA of
continuous current. Maximum ambient operating
temperature can be calculated based on the output
current and the voltage drop across the part. Given that
the input voltage is 3.3V, the output voltage is 2.8V and
the output current = 500mA.
The actual power dissipation of the regulator circuit can
be determined using the equation:
P
D = (VIN – VOUT) IOUT + VIN IGND
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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:
P
D = (3.3V – 2.8V) × 500mA
P
D = 0.25W
To determine the maximum ambient operating
temperature of the package, use the junction-to-ambient
thermal resistance of the device and the following basic
equation:
PD(MAX) =
TJ(MAX) - TA
JA
TJ(max) = 125°C, the maximum junction temperature of
the die θJA thermal resistance = 92.4°C/W.
Thermal Resistance
Substituting PD for PD(max) and solving for the ambient
operating temperature will give the maximum operating
conditions for the regulator circuit. The junction-to-
ambient thermal resistance for the minimum footprint is
92.4°C/W.
The maximum power dissipation must not be exceeded
for proper operation.
For example, when operating the MIC5353-2.8YMT at
an input voltage of 3.3V and 500mA load with a
minimum footprint layout, the maximum ambient
operating temperature TA can be determined as follows:
0.25W = (125°C – TA)/(92.4°C/W)
T
A=101°C
Therefore, a 2.8V application with 500mA of output
current can accept an ambient operating temperature of
101°C in a 1.6mm x 1.6mm Thin MLF® 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. This information can be found on
Micrel's website at:
http://www.micrel.com/_PDF/other/LDOBk_ds.pdf
Micrel, Inc. MIC5353
May 2010 9 M9999-052510
Typical Application Schematic (Fixed Output)
Bill of Materials
Item Part Number Manufacturer Description Qty.
06036D105KAT2A AVX(1)
C1,C3 GRM188R60J105KE19D muRata(2) Capacitor, 1µF Ceramic, 6.3V, X5R, Size 0603 2
06035C104KAT2A AVX(1)
C2 GRM188R71H104KA93D muRata(2) Capacitor, 0.1µF Ceramic, 50V, X5R, Size 0603 1
U1 MIC5353-XXYMT Micrel, Inc.(3) 500mA LDO, 1.6mm x 1.6mm Thin MLF® 1
Notes:
1. AVX: www.avx.com.
2. Murata Tel: www.murata.com.
3. Micrel, Inc.: www.micrel.com.
Micrel, Inc. MIC5353
May 2010 10 M9999-052510
Typical Application Schematic (Adjustable Output)
Bill of Materials
Item Part Number Manufacturer Description Qty.
06036D105KAT2A AVX(1)
C1,C3 GRM188R60J105KE19D muRata(2) Capacitor, 1µF Ceramic, 6.3V, X5R, Size 0603 2
06035C104KAT2A AVX(1)
C2 GRM188R71H104KA93D muRata(2) Capacitor, 0.1µF Ceramic, 50V, X5R, Size 0603 1
R1 CRCW060320K0FKEA Vishay(3) Resistor, 20k, 1%, 1/16W, Size 0603 1
R2 CRCW060310K0FKEA Vishay(3) Resistor, 10k, 1%, 1/16W, Size 0603 1
U1 MIC5353YMT Micrel, Inc.(4) Adjustable 500mA LDO, 1.6mm x 1.6mm Thin MLF® 1
Notes:
1. AVX: www.avx.com.
2. Murata Tel: www.murata.com.
3. Vishay Tel: www.vishay.com.
4. Micrel, Inc.: www.micrel.com.
Micrel, Inc. MIC5353
May 2010 11 M9999-052510
PCB Layout Recommendations
TOP LAYER
BOTTOM LAYER
Micrel, Inc. MIC5353
May 2010 12 M9999-052510
Package Information
6-Pin 1.6mm x 1.6mm Thin MLF® (MT)
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
The 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 Micrel for any damages resulting from such use or sale.
© 2010 Micrel, Incorporated.
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