MIC5355/6
Dual 500mA µCap Low Dropout,
Micropower Linear Regulator
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
March 2012 M9999-031512-A
General Description
The MIC5355/6 is an advanced dual, micropower, low
dropout linear regulator. The MIC5355/6 provides low
quiescent current operation, using only 70A with both
outputs enabled making it ideal for battery-powered
systems. In shutdown, the quiescent current drops to less
than 1µA. The MIC5355/6 provides two independently-
controlled high-performance 500mA LDOs with typical
dropout voltage of 350mV at rated load. In addition, the
MIC5355/6 is optimized to provide fast load and line
transient performance with low-ESR ceramic output
capacitors, requiring a minimum of only 2.2µF.
The MIC5356 also incorporates an active discharge
feature when the part is disabled that switches in a 30
load to pull down the output of the regulator. The
MIC5355/6 is available in fixed output voltages in a
thermally-enhanced 8-pin ePad MSOP package or 8-pin
ePad 3mm x 3mm MLF® package.
Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
Features
2.5V to 5.5V input voltage range
2% initial output accuracy
Wide output voltage range: 1.0V to 3.3V
Low quiescent current: 38µA per output
Very low quiescent current in shutdown: <1A typical
µCap stable with 2.2µF ceramic capacitor
Low dropout voltage: 350mV at 500mA
Excellent load/line transient response
Independent logic controlled enable pins
Output discharge circuit: MIC5356
Current and thermal limit protection
Power 8-pin ePad MSOP package or 8-pin ePad 3mm
x 3mm MLF® package
Applications
Smart phones
GPS, PMP, DSC
Notebooks and desktops
Digital TV
Portable electronics
_________________________________________________________________________________________________________________________
Typical Application
Micrel, Inc. MIC5355/6
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Ordering Information
Manufacturer Ordering
Part Number Part Number(1) Marking
Code Voltage(2)
Junction
Temperature
Range
Package
MIC5355-SGYMME MIC5355-3.3/1.8YMME 55SG 3.3V/1.8V –40° to +125°C 8-Pin ePad MSOP
MIC5355-S4YMME MIC5355-3.3/1.2YMME 55S4 3.3V/1.2V –40° to +125°C 8-Pin ePad MSOP
MIC5355-SCYMME MIC5355-3.3/1.0YMME 55SC 3.3V/1.0V –40° to +125°C 8-Pin ePad MSOP
MIC5355-G4YMME MIC5355-1.8/1.2YMME 55G4 1.8V/1.2V –40° to +125°C 8-Pin ePad MSOP
MIC5355-JGYMME MIC5355-2.5/1.8YMME 55JG 2.5V1.8V –40° to +125°C 8-Pin ePad MSOP
MIC5356-SGYMME MIC5356-3.3/1.8YMME 56SG 3.3V/1.8V –40° to +125°C 8-Pin ePad MSOP
MIC5356-S4YMME MIC5356-3.3/1.2YMME 56S4 3.3V/1.2V –40° to +125°C 8-Pin ePad MSOP
MIC5356-SCYMME MIC5356-3.3/1.0YMME 56SC 3.3V/1.0V –40° to +125°C 8-Pin ePad MSOP
MIC5356-G4YMME MIC5356-1.8/1.2YMME 56G4 1.8V/1.2V –40° to +125°C 8-Pin ePad MSOP
MIC5356-JGYMME MIC5356-2.5/1.8YMME 56JG 2.5V/1.8V –40° to +125°C 8-Pin ePad MSOP
MIC5356-MMYML MI5356-2.8/2.8YML M3M 2.8V/2.8V –40° to +125°C 8-Pin ePad 3mm x 3mm MLF®
MIC5356-MGYML MI5356-2.8/1.8YML M3G 2.8V/1.8V –40° to +125°C 8-Pin ePad 3mm x 3mm MLF®
Notes:
1. MIC5356 offers Auto-Discharge function.
2. Other voltage available. Contact Micrel for detail.
Pin Configuration
8-Pin ePad MSOP (MME) 8-Pin ePad 3mm x 3mm MLF® (ML)
Pin Description
Pin Number Pin Name Pin Function
1 VIN Supply Input.
2 GND Ground.
3 NC Not internally connected.
4 EN2 Enable Input LDO2. Active High Input. Logic High = On; Logic Low = Off; Do not leave floating.
5 EN1 Enable Input LDO1. Active High Input. Logic High = On; Logic Low = Off; Do not leave floating.
6 NC Not internally connected.
7 VOUT2 LDO2 Output.
8 VOUT1 LDO1 Output.
ePad HSPAD Heatsink pad. Connect to ground.
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Absolute Maximum Ratings(1)
Supply Voltage (VIN)........................................ –0.3V to +6V
Enable Voltage (VEN1, VEN2). ....................–0.3V to VIN +0.3V
Power Dissipation (PD)........................... Internally Limited(3)
Lead Temperature (soldering, 10sec.)....................... 260°C
Junction Temperature (TJ) ........................–40°C to +125°C
Storage Temperature (Ts) .........................–65°C to +150°C
ESD Rating(4)................................................. ESD Sensitive
Operating Ratings(2)
Supply Voltage (VIN)....................................... +2.5V to 5.5V
Enable Voltage (VEN1, VEN2). ................................... 0V to VIN
Junction Temperature (TJ) ........................ –40°C to +125°C
Junction Thermal Resistance
8-Pin ePad MSOP (θJA)..................................64.4°C/W
8-Pin ePad 3mm x 3mm MLF® (θJA)..................61°C/W
Electrical Characteristics(5)
VIN = VEN1 = VEN2 = VOUT +1V; higher of the two outputs; IOUTLDO1 = IOUTLDO2 = 100µA; COUT1 = COUT2= 2.2 µF; TJ = +25C,
bold values indicate –40°C to +125°C, unless noted.
Parameter Condition Min. Typ. Max. Units
Variation from nominal VOUT 2.0 +2.0
Output Voltage Accuracy
Variation from nominal VOUT 3.0 +3.0 %
Line Regulation VIN = VOUT + 1V to 5.5V, IOUT = 100µA 0.02 0.3 %/V
Load Regulation IOUT = 100µA to 500mA 0.3 1 %
IOUT = 50mA 40 100
Dropout Voltage IOUT = 500mA 350 800 mV
VEN1 = High; VEN2 = Low; IOUT1 = 0mA 38 53
VEN1 = Low; VEN2 = High; IOUT2 = 0mA 38 53
VEN1 = VEN2 = High; IOUT1 = IOUT2 = 0mA 70 100
VEN1 = High; VEN2 = Low; IOUT1 = 500mA 55 90
VEN1 = Low; VEN2 = High; IOUT2 = 500mA 55 90
Ground Pin Current
VEN1 = VEN2 = High; IOUT1 = IOUT2 = 500mA 105 200
µA
Shutdown Current VEN1 = VEN2 0.2V 0.05 1 µA
Ripple Rejection f = 1kHz; COUT = 2.2µF; IOUT = 250mA 60 dB
Current Limit VOUT = 0V 525 750 1050 mA
Output Voltage Noise COUT = 2.2µF, 10Hz to 100kHz 146 µVRMS
Auto-Discharge NFET
Resistance MIC5356 only; VEN1 = VEN2 = 0V; VIN = 3.6V; IOUT = 3mA 30
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) / JA. Exceeding the maximum allowable power
dissipation will result in excessive die temperature and the register 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.
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March 2012 4 M9999-031512-A
Electrical Characteristics(4)
VIN = VEN1 = VEN2 = VOUT +1V; higher of the two outputs; IOUTLDO1 = IOUTLDO2 = 100µA; COUT1 = COUT2= 2.2 µF; TJ = +25C,
bold values indicate –40°C to +125°C, unless noted.
Parameter Condition Min. Typ. Max. Units
Enable Inputs (EN1/EN2)
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 50 125 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. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.
4. Specification for packaged product only.
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Typical Characteristics
Power Supply Rejection Ratio
-80
-70
-60
-50
-40
-30
-20
-10
0
10 100 1000 10000 100000
FREQUENCY (Hz)
dB
V
EN
= V
IN
= 2.82V
V
OUT
= 1.8V
C
OUT
= 2.2µF
500mA
100µA
250mA
Output Voltage
vs. Input Voltage
2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3
2.5 3 3.5 4 4.5 5 5.5
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
100A
500mA
C
IN
= C
OUT
= 2.2F
Output Voltage
vs. Input Voltage
1.6
1.7
1.8
1.9
2
2.5 3 3.5 4 4.5 5 5.5
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
100A
500mA
C
IN
= C
OUT
= 2.2F
Output Voltage
vs. Output Current (V
OUT1
)
2.2
2.3
2.4
2.5
2.6
2.7
0 100 200 300 400 500
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE (V)
V
IN
= V
EN1
= 3.5V
V
OUT1
= 2.5V
C
IN
= C
OUT
= 2.2F
Output Voltage
vs. Output Current (V
OUT2
)
1.5
1.6
1.7
1.8
1.9
2
0 100 200 300 400 500
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE (V)
V
IN
= V
EN2
= 3.5V
V
OUT2
= 1.8V
C
IN
= C
OUT
= 2.2F
Ground Current vs.
Input Voltage (Single Output)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
2.5 3 3.5 4 4.5 5 5.5
INPUT VOLTAGE (V)
GROUND CURRENT
(μA)
500mA
NO LOAD
V
OUT2
= 1.8V
C
IN
= C
OUT
= 2.2F
V
EN1
= GND, V
EN2
= V
IN
Ground Current vs. Input
Voltage (Dual Output)
0
15
30
45
60
75
90
105
120
2.5 3 3.5 4 4.5 5 5.5
INPUT VOLTAGE (V)
GROUND CURRENT(μA)
500mA
NO LOAD
V
OUT1
= 2.5V, V
OUT2
= 1.8V
C
IN
= C
OUT
= 2.2F
V
EN1
= V
EN2
= V
IN
Ground Current
vs. Output Current
0
15
30
45
60
75
90
105
120
0 50 100 150 200 250 300 350 400 450 500
OUTPUT CURRENT (mA)
GROUND CURRENT(μA)
DUAL OUTPUT SINGLE OUTPUT
V
IN
= 3.5V
C
IN
= C
OUT
= 2.2F
Ground Current
vs. Temperature (Single Output)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
GROUND CURRENT (μA)
500mA
NO LOAD V
OUT1
=2.5V
V
EN1
= V
IN
= 3V
V
EN2
= GND
C
IN
= C
OUT
= 2.2F
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Typical Characteristics (Continued)
Ground Current
vs. Temperature (Dual Output)
0
20
40
60
80
100
120
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
GROUND CURRENT (μA)
NO LOAD
500mA
V
OUT1
= 2.5V, V
OUT2
= 1.8V
V
EN1
= V
EN2
= V
IN
= 3.5V
C
IN
= C
OUT
= 2.2F
Dropout Voltage
vs. Temperature
0
50
100
150
200
250
300
350
400
450
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
DROPOUT VOLTAGE (mV)
150mA
300mA
500mA
C
IN
= C
OUT
= 2.2F
50mA
Dropout Voltage
vs. Output Current
0
50
100
150
200
250
300
350
0 100 200 300 400 500
OUTPUT CURRENT (mA)
DROPOUT VOLTAGE (mV)
V
OUT1
= 2.5V
C
IN
= C
OUT
= 2.2F
Current Limit
vs. Input Voltage
600
650
700
750
800
850
900
2.533.544.555.5
INPUT VOLTAGE (V)
CURRENT LIMIT (mA)
V
OUT1
= 2.5V
V
OUT2
= 1.8V
C
IN
= C
OUT
= 2.2F
Output Noise Spectral Density
0.001
0.01
0.1
1
10 100 1000 10000 100000 1000000
FREQUENCY (Hz)
NOISE (µV/√Hz)
V
IN
= 3.5V
V
OUT2
= 1.81V
C
IN
- C
OUT
= 2.2µF
Noise (10Hz to 100Khz) =146µVrms
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Functional Characteristics
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March 2012 8 M9999-031512-A
Functional Diagrams
MIC5355 Block Diagram
MIC5356 Block Diagram
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March 2012 9 M9999-031512-A
Application Information
MIC5355/6 is a dual 500mA LDO. The MIC5356
includes an auto-discharge circuit for each LDO output
that is activated when the output is disabled. The
MIC5355/6 regulator is fully protected from damage due
to fault conditions through linear current limiting and
thermal shutdown.
Input Capacitor
The MIC5355/6 is a high-performance, high-bandwidth
device. A 2.2µF input capacitor from the input pin to
ground is required to provide stability. Low-ESR ceramic
capacitors provide optimal performance in small board
area. 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. X5R or X7R dielectrics are
recommended for the input capacitor. Y5V dielectrics
lose most of their capacitance over temperature and are
therefore not recommended.
Output Capacitor
The MIC5355/6 requires an output capacitor of 2.2µF 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, but performance has
been optimized for a 2.2µF ceramic output capacitor and
does not improve significantly with larger capacitance.
X7R and X5R dielectric ceramic capacitors are
recommended because of their temperature
performance. X7R 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 to ensure the same minimum
capacitance over the equivalent operating temperature
range.
No Load Stability
Unlike many other voltage regulators, the MIC5355/6 will
remain stable and in regulation with no load.
Enable/Shutdown
The MIC5355/6 comes with two active high enable pins
that allow each regulator to be disabled independently.
Forcing the enable pin low disables the regulator and
places it into an off mode current state drawing virtually
zero current. When disabled, the MIC5356 switches an
internal 30 load on the regulator output to discharge
the external capacitor.
Forcing the enable pin high enables the output voltage.
The active high enable pin uses CMOS technology and
cannot be left floating. A floating enable pin may cause
an indeterminate state on the output.
Thermal Considerations
The MIC5355/6 is designed to provide two 500mA
continuous current outputs in a small package.
Maximum operating temperature can be calculated
based on the output currents and the voltage drop
across the part. For example, if the input voltage is 3.0V,
VOUT1 = 2.5V, VOUT2 = 1.8V and each with an output
current = 500mA. The actual power dissipation of the
regulator circuit can be determined using the equation:
PD = (VIN VOUT1) IOUT (VIN VOUT2) IOUT2 VIN IGND
Because this is CMOS device and the ground current is
typically <100µA over the load range, the power
dissipation contributed by the ground current is <1%
which can be ignored for this calculation:
PD = (3.0V – 2.5V) × 500mA + (3.0V – 1.8V) × 500mA
P
D = 0.85W
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:
JA
AJ(MAX)
D(MAX)
TT
P
TJ(MAX) = 125°C
JA = 64.4°C/W
Micrel, Inc. MIC5355/6
March 2012 10 M9999-031512-A
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 64.4°C/W.
The maximum power dissipation must not be
exceeded for proper operation.
For example, when operating a 2.5V/1.8V application
with an input voltage of 3.0V and 500mA at each
output with a minimum footprint layout, the maximum
ambient operating temperature TA can be determined
as follows:
0.85W = (125°C – TA)/(64.4°C/W)
TA = 70.3°C
Therefore, a MIC5355-JGYMME application with
500mA at each output current can accept an ambient
operating temperature of 70.3°C in a small 8-pin ePad
MSOP 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
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March 2012 11 M9999-031512-A
Typical Application Schematic
Bill of Materials
Item Part Number Manufacturer Description Qty.
C1, C2, C3 C1005X5R0J225M TDK(1) 2.2µF ceramic capacitor, 6.3V, X5R, size 0402 3
U1 MIC5355/6-xxYMME Micrel, Inc.(2) Dual 500mA µCap Low-Dropout, Micropower Linear Regulator 1
Notes:
1. TDK: www.tdk.com.
2. Micrel, Inc.: www.micrel.com.
Micrel, Inc. MIC5355/6
March 2012 12 M9999-031512-A
Typical Application Schematic (Continued)
Bill of Materials
Item Part Number Manufacturer Description Qty.
C1, C2, C3 C1005X5R0J225M TDK(1) 2.2µF ceramic capacitor, 6.3V, X5R, size 0402 3
U1 MIC5355/6-xxYML Micrel, Inc.(2) Dual 500mA µCap Low-Dropout, Micropower Linear Regulator 1
Notes:
3. TDK: www.tdk.com.
4. Micrel, Inc.: www.micrel.com.
Micrel, Inc. MIC5355/6
March 2012 13 M9999-031512-A
PCB Layout Recommendations (MME Package)
Top Layer
Bottom Layer
Micrel, Inc. MIC5355/6
March 2012 14 M9999-031512-A
PCB Layout Recommendations (ML Package)
Top Layer
Bottom Layer
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March 2012 15 M9999-031512-A
Package Information
8-Pin ePad MSOP (MME)
8-Pin ePad 3mm x 3mm MLF® (ML)
Micrel, Inc. MIC5355/6
March 2012 16 M9999-031512-A
Package Information (Continued)
Red circle indicates Thermal Via. Size should be .300 .350mm in diameter, 1/00mm pitch, and it should be connected to
GND plane for maximum thermal performance.
8-Pin ePad MSOP (MME)
Micrel, Inc. MIC5355/6
March 2012 17 M9999-031512-A
Package Information (Continued)
Red circle indicates Thermal Via. Size should be .300 .350mm in diameter, 1/00mm pitch, and it should be connected to
GND plane for maximum thermal performance.
8-Pin ePad 3mm x 3mm MLF® (ML)
Micrel, Inc. MIC5355/6
March 2012 18 M9999-031512-A
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
Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This
information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry,
specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual
property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability
whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties
relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right.
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.
© 2012 Micrel, Incorporated.
