Micrel MIC5357 High performance, low noise dual 500ma uldoâ ¢ Datasheet

MIC5357
High Performance, Low Noise Dual
500mA ULDO™
General Description
Features
The MIC5357 is a tiny Dual Ultra Low Dropout (ULDO™)
linear regulator ideally suited for portable electronics due
to its low output noise. The MIC5357 provides two
independently controlled high performance 500mA LDOs
with typical dropout voltage of 130mV at rated load. In
addition, the MIC5357 provides a bypass pin to reduce the
output noise.
The MIC5357 is designed to be stable with small ceramic
output capacitors thereby reducing required board space
and component cost. The combination of extremely low
dropout voltage, low output noise and exceptional thermal
package characteristics makes it ideal for powering RF
and noise sensitive circuitry, cellular phone camera
modules, imaging sensors for digital still cameras, PDAs,
MP3 players and WebCam applications.
The MIC5357 ULDO™ is available in fixed output voltages
in the small 8-pin ePad MSOP package. Additional voltage
options are available. For more information, contact Micrel
marketing.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
•
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•
•
•
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•
•
•
•
2.6V to 5.5V input voltage range
Ultra low dropout voltage: 130mV @ 500mA
Ultra low output noise: 51µVRMS
±2% initial output accuracy
Small 8-pin ePad MSOP package
Excellent Load/Line transient response
Fast start up time: 38µs
µCap stable with 2.2µF ceramic capacitors
Thermal shutdown protection
Low quiescent current: 160µA with both outputs at
maximum load
• Current-limit protection
Applications
•
•
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Battery-Powered Applications
PDAs
GPS receivers
Portable electronics
Portable media players
Digital still and video cameras
_________________________________________________________________________________________________________________________
Typical Application
RF Power Supply Circuit
ULDO is a trademark of Micrel, 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
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MIC5357
Block Diagram
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MIC5357
Ordering Information
Part Number (1)
Manufacturing Part
Number
Marking
MIC5357-3.3/2.8YMME
MIC5357-SMYMME
MIC5357-3.3/1.8YMME
Voltage(V)
VOUT1
VOUT2
Junction Temperature
Range
57SM
3.3V
2.8V
–40°C to +125°C
8-Pin ePAD MSOP
MIC5357-SGYMME
57SG
3.3V
1.8V
–40°C to +125°C
8-Pin ePAD MSOP
MIC5357-2.8/1.8YMME
MIC5357-MGYMME
57MG
2.8V
1.8V
–40°C to +125°C
8-Pin ePAD MSOP
MIC5357-1.8/1.5YMME
MIC5357-GFYMME
57GF
1.8V
1.5V
–40°C to +125°C
8-Pin ePAD MSOP
Package
Notes
1.
For other voltage options contact Micrel Marketing.
Pin Configuration
8-Pin ePAD MSOP (MME)
TOP VIEW
Pin Description
Pin Number
Pin Name
Pin Function
1
VIN
Supply Input.
2
GND
Ground.
3
BYP
Reference Bypass: Connect external 0.1µF to GND to reduce output noise.
May be left open when bypass capacitor is not required.
4
EN2
Enable Input (regulator 2). Active High Input. Logic High = On; Logic Low = Off;
Do not leave floating.
5
EN1
Enable Input (regulator 1). Active High Input. Logic High = On; Logic Low = Off;
Do not leave floating.
6
NC
Not internally connected.
7
VOUT2
Regulator Output – LDO2.
8
VOUT1
Regulator Output – LDO1.
ePAD
HS Pad
Heatsink Pad internally connected to ground.
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MIC5357
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Voltage (VIN) ........................................ −0.3V to +6V
Enable Input Voltage (VEN1 , VEN2).....................−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
Supply Voltage (VIN)..................................... +2.6V to +5.5V
Enable Input Voltage (VEN1, VEN2) .......................... 0V to VIN
Junction Temperature ............................... –40°C to +125°C
Junction Thermal Resistance
8-Pin ePAD MSOP (θJA) .................................64.4°C/W
Electrical Characteristics(5)
VIN = VEN1 = VEN2 = VOUT + 1.0V; higher of the two regulator outputs, IOUTLDO1 = IOUTLDO2 = 100µA; COUT1 = COUT2 = 2.2µF; CBYP = 0.1µF;
TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted.
Parameter
Output Voltage Accuracy
Conditions
Min.
Typ.
Max.
Variation from nominal VOUT
-2.0
+2.0
Variation from nominal VOUT; –40°C to +125°C
-3.0
+3.0
Units
%
Line Regulation
VIN = VOUT + 1V to 5.5V; IOUT = 100µA
0.05
0.3
0.6
%/V
Load Regulation
IOUT1&2 =100µA to 500mA
0.7
2.5
%
IOUT1,2 = 100µA
0.1
IOUT1,2 = 50mA
12
50
mV
IOUT1,2 = 500mA
130
300
VEN1 ≥ 1.2V; VEN2 ≤ 0.2V; IOUT = 0mA to 500mA
95
175
VEN1 ≤ 0.2V; VEN2 ≥ 1.2V; IOUT2 = 0mA to 500mA
95
175
VEN1 = VEN2 ≥ 1.2V; IOUT1 = 500mA, IOUT2 = 500mA
160
240
VEN1 = VEN2 = 0V
0.01
2
Dropout Voltage (6)
Ground Current
Ground Current in Shutdown
Ripple Rejection
Current Limit
Output Voltage Noise
f = 1kHz; COUT = 2.2µF; CBYP = 0.1µF
70
f = 20kHz; COUT = 2.2µF; CBYP = 0.1µF
45
µA
dB
VOUT1 = 0V
550
950
1300
VOUT2 = 0V
550
950
1300
COUT = 2.2µF; CBYP = 0.1µF; 10Hz to 100kHz
µA
51
mA
µVRMS
Enable Inputs (EN1 / EN2)
Enable Input Voltage
Enable Input Current
0.2
Logic Low
1.2
Logic High
VIL ≤ 0.2V
0.01
VIH ≥ 1.2V
0.01
V
µA
Turn-on Time (See Timing Diagram)
Turn-on Time (LDO1 and 2)
COUT = 2.2µF; CBYP = 0.1µF
38
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 1.5kΩ 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 VOUT. For outputs below
2.6V, the dropout voltage is the input-to-output differential with the minimum input voltage 2.6V.
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Typical Characteristics
Ground Current
vs. Output Current (VOUT1)
Ground Current
vs. Output Current (VOUT2)
100
100
Ground Current vs.
Temperature(Dual Outputs)
180
IOUT1=500mA , IOUT2=500mA
95
90
VIN =4.3V
85
VOUT1=3.3V
GROUND CURRENT (μA)
GROUND CURRENT (μA)
GROUND CURRENT (μA)
170
95
90
VIN =4.3V
85
VOUT2=2.8V
150
140
130
120
110
IOUT1=500mA
100
90
80
CIN =COUT=2.2μF
CIN =COUT=2.2μF
160
70
80
-40 -20
80
0
50 100 150 200 250 300 350 400 450 500
0
OUTPUT CURRENT (mA)
Output Voltage
vs. Input Voltage
3.1
3
500mA
VOUT1=3.3V
100μA
2.8
2.7
500mA
2.6
VOUT2=2.8V
CIN =COUT=2.2μF
2.6
OUTPUT VOLTAGE (V)
3.2
2.7
2.9
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
100μA
2.8
CIN =COUT=2.2μF
3.5
3.4
3
3.5
4
4.5
80 100 120
5
3.2
3.1
V IN =4.3V
CIN =COUT=2.2μF
3
2.9
V OUT2
2.8
2.7
2.6
2.5
0
2.5
5.5
VOUT1
3.3
2.5
2.5
2.5
60
3.6
3.5
2.9
40
Output Voltage
vs. Output Current
3
3.6
3.3
20
TEMPERATURE (°C)
OUTPUT CURRENT (mA)
Output Voltage
vs. Input Voltage
3.4
0
50 100 150 200 250 300 350 400 450 500
3
3.5
4
4.5
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Dropout Voltage
vs. Temperature
Dropout Voltage
vs. Output Current
5
5.5
100
200
300
400
500
OUTPUT CURRENT (mA)
Current Limit
vs. Input Voltage
1200
CIN =COUT=2.2μF
120
500mA
105
300mA
90
75
150mA
60
45
30
50mA
15
105
90
75
60
`
45
30
VOUT1=3.3V
15
-40
-20
0
20
40
60
80
100
0
120
100
TEMPERATURE (°C)
100µA
NOISE (uV/√Hz)
dB
-50
-40
-30 VEN1=VIN =4.74V
-10
V OUT1=3.3V
COUT1=2.2µF
0.1
0.01
0.001
0
100
1000
10000
FREQUENCY(Hz)
January 2011
CIN =COUT=2.2μF
500
2.5
3
3.5
4
4.5
5
5.5
INPUT VOLTAGE (V)
100000
V IN=4.7V
V OUT2=1.8V
CBY P=0.1µA
10
900
1
-60
-20
VOUT1=3.3V
950
10
300mA
500mA
-70
400
1000
Output Noise
Spectral Density
150mA
-80
300
1050
800
OUTPUT CURRENT (mA)
Power Supply Rejection Ratio
-90
200
1100
850
CIN =COUT=2.2μF
0
0
VOUT2=2.8V
1150
120
CURRENT LIMIT (mA)
DROPOUT VOLTAGE (mV)
135
DROPOUT VOLTAGE (mV)
150
CIN-COUT=2.2µF/6.3V
IL=250mA
Noise Output (10Hz to
100Khz)=51.16µVrms
10
100
1000
10000
100000 1000000
FREQUENCY (Hz)
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MIC5357
Functional Characteristics
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MIC5357
A unique, quick start circuit allows the MIC5357 to drive
a large capacitor on the bypass pin without significantly
slowing the turn on time.
Applications Information
Enable/Shutdown
The MIC5357 is provided with dual active high enable
pins that allow each regulator to be enabled
independently. Forcing both enable pins low disables the
regulators 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.
No-Load Stability
Unlike many other voltage regulators, the MIC5357 will
remain stable with no load. This is especially important
in CMOS RAM keep alive applications.
Thermal Considerations
The MIC5357 is designed to provide 500mA of
continuous current for VOUT1 and 500mA for VOUT2 in a
small package. The 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 3.6V, the output voltage is 3.3V for
VOUT1, 2.8V for VOUT2 and the output current of 500mA
and 500mA respectively. The actual power dissipation of
the regulator circuit can be determined using the
equation:
Input Capacitor
The MIC5357 is a high performance, high bandwidth
device. Therefore, it requires a well bypassed input
supply for optimal performance. A 2.2µF capacitor is
required from the input to ground to provide stability.
Low ESR ceramic capacitors provide optimal
performance at a minimum of space. 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.
PD = (VIN – VOUT1) IOUT1 + (VIN – VOUT2) IOUT2+ VIN IGND
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.
Output Capacitor
The MIC5357 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/X5R dielectric type ceramic capacitors are
recommended because of their superior 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 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.
PD = (3.6V – 3.3V) × 500mA + (3.6V -2.8) × 500mA
PD = 0.55W
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 = 64.4°C/W.
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.
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MIC5357
Thermal Resistance
Therefore, a 3.3V/2.8V application with 500mA and
500mA output currents can accept an ambient operating
temperature of 89.6°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
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 the MIC5357 at an input
voltage of 3.6V and 500mA on VOUT1 and 500mA on
VOUT2, the maximum ambient operating temperature TA
can be determined as follows:
0.55W = (125°C – TA)/(64.4°C/W)
TA = 89.6°C
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Typical Application Schematic
Bill of Materials
Item
C1, C2,C3
C4
U1
Part Number
Manufacturer
C1005X5R0J225M
TDK(1)
VJ0402Y104KXX
MIC5357-xxYMME
(2)
Vishay
Micrel, Inc.
(3)
Description
Qty.
Capacitor, 2.2µF Ceramic, 6.3V, X5R, Size 0402
3
Capacitor, 0.1µF Ceramic, 25V, X7R, Size 0402
1
High Performance, Low Noise Dual 500mA ULDO™
1
Notes:
1. TDK: www.tdk.com.
2. Vishay Tel: www.vishay.com.
3. Micrel, Inc.: www.micrel.com.
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MIC5357
PCB Layout Recommendations
Top Layer
Bottom Layer
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MIC5357
Package Information
8-Pin ePAD MSOP (MME)
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.
© 2011 Micrel, Incorporated.
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