MIC37252
2.5A, Low Voltage µCap LDO Regulator
General Description
The Micrel MIC37252 is a 2.5A low-dropout linear voltage
regulator that provides a low voltage, high current output
with a minimum of external components. It offers high
precision, low dropout and low ground current.
The MIC37252 operates from an input voltage of 3.0V
to6.0V. It is designed to drive digital circuits requiring low
voltage at high currents (i.e., PLDs, DSP, microcontroller,
etc.). It is available in an adjustable output voltage capable
of 1.24V to 5.5V.
Features of the MIC37252 LDO include thermal and
current limit protection, and reverse current and reverse
battery protection.
Junction temperature range of the MIC37252 is from
–40°C to +125°C.
For higher currents see the MIC3730x family of LDOs.
Features
•
•
•
•
•
•
•
•
•
•
2.5A minimum guaranteed output current
Ideal for 3.3V to 1.8V conversion
Stable with ceramic or tantalum capacitor
±2.0% initial output tolerance
Dropout voltage = 550mV @ 2.5A
Excellent line and load regulation specifications
Logic controlled shutdown
Thermal shutdown and current limit protection
Reverse-leakage protection
S-Pak and TO-263 packages
Applications
•
•
•
•
•
LDO linear regulator for low-voltage digital IC
PC add-in cards
High efficiency linear power supplies
SMPS post regulator
Battery charger
____________________________________________________________________________________________________________
Typical Application
Adjustable Regulator
SuperSwitcher and Super ßeta PNP are trademarks 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
February 2006
M9999-021606
(408) 955-1690
Micrel, Inc.
MIC37252
Ordering Information
Part Number
Standard
MIC37252BR
MIC37252BU
RoHS Compliant**
MIC37252WR
MIC37252WU
Output
Current
2.5A
2.5A
Voltage*
Adj.
Adj.
Junction
Temperature Range
–40° to +125°C
–40° to +125°C
Package
S-Pak-5
TO-263-5
*For other voltages, please contact Micrel Marketing.
**RoHS compliant with “high melting solder” exemption.
Pin Configuration
S-PAK5 (R)
TO-263 (U)
Pin Description
Pin Number
1
2
3
4
5
Pin Name
EN
VIN
GND
VOUT
ADJ
Pin Function
Enable (Input): CMOS compatible input. Logic high = enable, logic low =
shutdown.
Input voltage which supplies current to the output power device.
Ground (TAB is connected to ground on S-Pak).
Regulator Output.
Adjustable regulator feedback input. Connect to resistor voltage divider.
February 2006
2
M9999-021606
(408) 955-1690
Micrel, Inc.
MIC37252
Absolute Maximum Ratings
(1)
Supply Voltage (V
IN
) ......................................................6.5V
Enable Input Voltage (V
EN
)............................................6.5V
Power Dissipation .....................................Internally Limited
Junction Temperature .........................–40°C
≤
T
J
≤
+125°C
Storage Temperature ..........................–65°C
≤
T
J
≤
+150°C
Lead Temperature (soldering, 5sec.)......................... 260°C
EDS
(3)
Operating Ratings
(2)
Supply voltage (V
IN
) ......................................... 3.0V to 6.0V
Enable Input Voltage (V
EN
).................................. 0V to 6.0V
Junction Temperature Range .............–40°C
≤
T
J
≤
+125°C
Maximum Power Dissipation
(4)
Package Thermal Resistance
S-Pak (θ
JC
) ..........................................................2°C/W
TO-263-5 (θ
JC
).....................................................2°C/W
Electrical Characteristics
(5)
T
A
= 25°C with V
IN
= V
OUT
+ 1V; V
EN
= V
IN
; I
L
= 10mA,
bold
values indicate –40°C< T
J
< +125°C, unless otherwise noted.
Parameter
Output Voltage Accuracy
Output Voltage Line Regulation
Output Voltage Load Regulation
V
IN
– V
OUT
; Dropout Voltage,
Note 6
Ground Pin Current,
Note 7
Ground Pin Current in Shutdown
Current Limit
Start-up Time
Enable Input
Enable Input Threshold
Enable Pin Input Current
Regulator enable
Regulator shutdown
V
IL
≤
0.8V (Regulator shutdown)
V
IH
≥
2.25V (Regulator enable)
Reference Voltage
Adjust Pin Bias Current
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. Device is ESD sensitive. Handling precautions recommended.
4. P
D(max)
= T
J(max)
– T
A
) /
θ
JA
, where
θ
JA
, depends upon the printed circuit layout. See “Applications Information.”
5. Specification for packaged product only
6. V
DO
= V
IN
– V
OUT
when V
OUT
decreased to 98% of its nominal output voltage with V
IN
= V
OUT
+ 1V. For output voltages below 2V, dropout voltage
specification does not apply due to a minimum input operating voltage of 3V
7. I
GND
is the quiescent current. I
IN
= I
GND
+ I
OUT
.
Condition
I
L
= 10mA
10mA < I
OUT
< I
L(max)
, V
OUT
+ 1
≤
V
IN
≤
6V
V
IN
= V
OUT
+ 1.0V to 6.0V, I
L
= 10mA
I
L
= 10mA to 2.5A
I
L
= 1.5A
I
L
= 2.5A
I
L
= 2.5A
V
IL
≤
0.5V, V
IN
= V
OUT
+ 1V
V
OUT
= 0; V
IN
= 3.3V
V
EN
= V
IN
, I
OUT
= 10mA, C
OUT
= 47µF
Min
-2
-3
Typ
Max
+2
+3
Units
%
%
%
%
mV
mV
mA
µA
A
0.02
0.2
400
550
40
1.0
3
150
2.25
0.5
1
500
1000
60
250
µs
V
0.8
2
4
1
1.215
1.202
10
1.240
40
30
1.265
1.277
80
120
V
µA
µA
µA
V
V
nA
nA
February 2006
3
M9999-021606
(408) 955-1690
Micrel, Inc.
MIC37252
Typical Characteristics
70
60
50
PRSS (dB)
40
30
20 C
OUT
= 100µF Ceramic
V = 3.3V
10
IN
V
OUT
= 1.8V
0
1 10 100 1k 10k 100k 1M
FREQUENCY (Hz)
100mA
1A
PSRR
70
60
50
PSRR (dB)
40
30
1A
2.5A
PSRR
DROPOUT VOLTAGE (mV)
100mA
600
500
400
300
200
100
0
0
Dropout Voltage
V
OUT
= 3.3V
2.5A
20 C
OUT
= 47µF
V = 3.3V
10
IN
V
OUT
= 1.8V
0
1 10 100 1k 10k 100k 1M
FREQUENCY (Hz)
0.5
1
1.5
2
2.5
OUTPUT CURRENT (A)
600
DROPOUT VOLTAGE (mV)
500
400
300
200
100
Dropout
vs. Temperature
OUTPUT VOLTAGE (V)
3.3V
OUT
2.5A load
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE °C)
(
1.85
1.84
1.83
1.82
1.81
1.80
1.79
1.78
1.77
1.76
1.75
-40 -20 0 20 40 60 80 100 120
TEMPERATURE °C)
(
Output Voltage
vs. Temperature
18
ENABLE CURRENT (µA)
16
14
12
10
8
6
4
2
Enable Pin Current
vs. Temperature
100mA Load
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE °C)
(
SHORT CIRCUIT CURRENT (A)
4
3.5
3
2.5
2
1.5
1
0.5
Short Circuit Current
vs. Temperature
GROUND CURRENT (mA)
V
OUT
= 0V
V
IN
= 4.3V
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE T (°C)
J
50
45
40
35
30
25
20
15
10
5
0
0
Ground Current
vs. Supply Voltage
GROUND CURRENT (mA)
2.5A
1.5A
0.5A
1
2
3
4
SUPPLY VOLTAGE (V)
5
50
2.5A Load
45
40
35
30
25
20
15 1A Load
10
5 10mA Load
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE °C)
(
Ground Current
vs. Temperature
50
45
40
35
30
25
20
15
10
5
0
Ground Current
vs. Output Current
OUTPUT VOLTAGE (V)
0
0.5
1
1.5
2
2.5
OUTPUT CURRENT (A)
2.510
2.508
2.506
2.504
2.502
2.500
2.498
2.496
2.494
2.492 2.5V
OUT
2.490
0
0.5
1
1.5
2
2.5
OUTPUT CURRENT (A)
Output Voltage
vs. Load Current
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.00
Dropout Characteristics
0.5A
1.5A
GROUND CURRENT (mA)
OUTPUT VOLTAGE (V)
2.5A
1
2
3
SUPPLY VOLTAGE (V)
4
February 2006
4
M9999-021606
(408) 955-1690
Micrel, Inc.
MIC37252
Functional Characteristics
LoadTransient Response
OUTPUT VOLTAGE
(100mV/div.)
V
IN
= 3.3V
V
OUT
= 1.8V
C
OUT
= 47µF
OUTPUT VOLTAGE
(200mV/div.)
V
IN
= 3.3V
V
OUT
= 1.8V
C
OUT
= 47µF
LoadTransient Response
OUTPUT CURRENT
(1A/div.)
2.5A
2A
OUTPUT CURRENT
(1A/div.)
10mA
10mA
TIME (400
µs/div.)
TIME (400
µs/div.)
Line Transient Response
OUTPUT VOLTAGE
(20mV/div.)
5V
3.3V
INPUT VOLTAGE
(2V/div.)
TIME (100
µs/div.)
February 2006
5
M9999-021606
(408) 955-1690
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