MIC5237
500mA Low-Dropout Regulator
General Description
Features
The MIC5237 is a general-purpose low-dropout regulator
•
Guaranteed 500mA output over the full operating
capable of 500mA output current with better than 3%
temperature range
output voltage accuracy. Using Micrel’s proprietary Super
•
Low 300mV typical dropout voltage at full load
ßeta PNP
®
process with a PNP pass element, these
•
Extremely tight load and line regulation
regulators feature less than 300mV dropout voltage and
•
Current and thermal limiting
typically 8mA ground current at full load.
•
Reversed-battery protection
Designed for applications that require moderate current
•
TO-220 and TO-263 packages
over a broad input voltage range, including hand-held and
battery-powered devices, the MIC5237 is intended for
•
Low temperature coefficient
applications that can tolerate moderate voltage drop at
•
No-load stability
higher current.
•
Low-noise output
Key features include low ground current to help prolong
battery life, reversed-battery protection, current limiting,
over-temperature shutdown, and thermally efficient
Applications
packaging. The MIC5237 is available in fixed output
•
Portable and laptop computers
voltages only.
•
Desktop computer
For space-critical applications and improved performance,
•
Battery chargers
see the MIC5209 and MIC5219. For output current
•
SMPS post-regulator/dc-to-dc modules
requirements up to 750mA, see the MIC2937.
•
Consumer and personal electronics
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
___________________________________________________________________________________________________________
Typical Application
Super
βeta
PNP is a registered 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
September 2007
M9999-090607-C
Micrel, Inc.
MIC5237
Ordering Information
Part Number
Standard
MIC5237-2.5BU
MIC5237-3.3BU
MIC5237-5.0BT
MIC5237-5.0BU
Pb-Free
MIC5237-2.5YU
MIC5237-3.3YU
MIC5237-5.0YT
MIC5237-5.0YU
2.5V
3.3V
5.0V
5.0V
–40° to +125°C
–40° to +125°C
–40° to +125°C
–40° to +125°C
TO-263-3
TO-263-3
TO-220-3
TO-263-3
Voltage
Junction Temp. Range
Package
Pin Configuration
TO-220-3 (T)
TO-263-3 (U)
Pin Description
Pin Number
1
2, TAB
3
Pin Name
IN
GND
OUT
Pin Function
Supply Input.
Ground: TO-220 and TO-263 pin 2 and TAB are internally connected.
Regulator Output.
September 2007
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M9999-090607-C
Micrel, Inc.
MIC5237
Absolute Maximum Ratings
(1)
Supply Voltage (V
IN
) ..........................................–20 to +20V
Power Dissipation (P
D
). .............................Internally Limited
Lead Temperature (soldering, 5 sec.)........................ 260°C
Operating Ratings
Supply Voltage (V
IN
)...................................... +2.5V to +16V
Junction Temperature (T
J
) ........................ –40°C to +125°C
Package Thermal Resistance
TO-220 (θ
JA
).......................................................55°C/W
TO-220 (θ
JC
) ........................................................3°C/W
TO-263 (θ
JC
) ........................................................3°C/W
Electrical Characteristics
V
IN
= V
OUT
+ 1.0V; C
OUT
= 4.7µF; I
OUT
= 100µA; T
J
= 25°C,
bold
values indicate –40°C< T
J
< +125°C, unless noted.
Symbol
V
OUT
∆V
OUT
/∆T
∆V
OUT
/V
OUT
∆V
OUT
/V
OUT
V
IN
– V
OUT
Parameter
Output Voltage Accuracy
Output Voltage
Temperature Coefficient
Line Regulation
Load Regulation
Dropout Voltage,
Note 4
Condition
variation from nominal V
OUT
Note 2
V
IN
= V
OUT
+ 1V to 16V
I
OUT
= 100µA to 500mA,
Note 3
I
OUT
= 100µA
I
OUT
= 50mA
I
OUT
= 150mA
I
OUT
= 500mA
I
GND
Ground Pin Current,
Note 5
I
OUT
= 100µA
I
OUT
= 50mA
I
OUT
= 150mA
I
OUT
= 500mA
PSRR
I
LIMIT
∆V
OUT
/∆P
D
e
no
Ripple Rejection
Current Limit
Thermal Regulation
Output Noise
f = 120Hz
V
OUT
= 0V
Note 6
V
OUT
= 5.0V, I
OUT
= 50Ma, C
OUT
= 2.2µF
Min
–3
–5
40
0.05
0.1
0.5
0.7
70
90
190
280
350
450
600
700
130
170
650
900
2.5
3.0
15
20
900
1000
Typ
Max
3
5
Units
%
%
ppm/°C
%/V
%/V
%
%
mV
mV
mV
mV
mV
mV
mV
mV
µA
µA
µA
µA
mA
mA
mA
mA
dB
mA
mA
%/W
nV/√Hz
0.015
0.05
10
115
165
300
80
350
1.8
8
75
700
0.05
500
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Micrel, Inc.
MIC5237
Notes:
1. Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating
the device outside of its operating ratings. The maximum allowable power dissipation is a function of the maximum junction temperature, T
J(max)
, the
junction-to-ambient thermal resistance,
θ
JA
, and the ambient temperature, T
A
. The maximum allowable power dissipation at any ambient temperature
is calculated using: P
D(max)
= (T
J(max)
–T
A
) ÷
θ
JA
. Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the
regulator will go into thermal shutdown. See the
“Thermal Considerations”
section for details.
2. Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.
3. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load range from
100µA to 500mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification.
4. Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1Vdifferential.
5. Ground pin current is the regulator quiescent current plus pass transistor base current. The total current drawn from the supply is the sum of the load
current plus the ground pin current.
6. Thermal regulation is defined as the change in output voltage at a time “t” after a change in power dissipation is applied, excluding load or line
regulation effects. Specifications are for a 500mA load pulse at V
IN
= 16V for t = 10ms.
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MIC5237
Typical Characteristics
0
-20
PSRR (dB)
-40
-60
-80
I
OUT
= 100µA
C
OUT
= 1µF
Power Supply
Rejection Ratio
V
IN
= 6V
V
OUT
= 5V
PSRR (dB)
0
-20
-40
-60
-80
Power Supply
Rejection Ratio
V
IN
= 6V
V
OUT
= 5V
PSRR (dB)
0
-20
-40
-60
-80
Power Supply
Rejection Ratio
V
IN
= 6V
V
OUT
= 5V
-100
1E+11E+21E+31E+41E+51E+61E+7
10 100 1k 10k 100k 1M 10M
FREQUENCY (Hz)
-100
1E+11E+21E+31E+41E+51E+61E+7
10 100 1k 10k 100k 1M 10M
FREQUENCY (Hz)
I
OUT
= 1mA
C
OUT
= 1µF
I
OUT
= 100mA
C
OUT
= 1µF
-100
1E+11E+21E+31E+41E+51E+61E+7
10 100 1k 10k 100k 1M 10M
FREQUENCY (Hz)
60
RIPPLE REJECTION (dB)
50
40
30
20
10
0
Power Supply Ripple Rejection
vs. Voltage Drop
10
1
NOISE (µV/ Hz)
0.1
0.01
Noise Performance
100mA
10mA
1mA
10mA
I
OUT
= 100mA
C
OUT
= 1µF
0.1
0.2
0.3
VOLTAGE DROP (V)
0.4
0
V
OUT
= 5V
1mA
0.001 C
= 10µF
OUT
electrolytic
0.0001
10 100 1k 10k 100k 1M 10M
1E+11E+2 1E+31E+4 1E+51E+6 1E+7
FREQUENCY (Hz)
September 2007
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M9999-090607-C
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