MIC5248
Micrel
November 2002
1
MIC5248
Typical Application
1
5
2
3
4
C
47k
OUT
Enable
Shutdown
EN
V
OUT
MIC5248-x.xBM5
EN (pin 3) may be
connected directly
to IN (pin 1).
V
IN
PG
Low-Noise Regulator Application
MIC5248
150mA
Cap CMOS LDO Regulator w/Power Good
Final Information
Features
Power Good indicator
Load independent, ultra-low ground current: 100
A
150mA output current
Current limiting
Thermal shutdown
Tight load and line regulation
"Zero" off-mode current
Stability with low-ESR capacitors
Fast transient response
TTL-logic-controlled enable input
Applications
Processor power-up sequencing
Laptop, notebook, and palmtop computers
PCMCIA V
CC
and V
PP
regulation/switching
Micrel, Inc. 1849 Fortune Drive San Jose, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 944-0970 http://www.micrel.com
IttyBitty is a trademark of Micrel, Inc.
Ordering Information
Part Number
Marking
Voltage
Junction Temp. Range*
Package
MIC5248-1.2BM5
LV12
1.2
40
C to +125
C
SOT-23-5
MIC5248-1.2YM5
KV12
1.2
40
C to +125
C,
SOT-23-5
Lead-free
Other voltages available. Contact Micrel for details.
General Description
The MIC5248 is an efficient, precise CMOS voltage regulator
with power good output. The MIC5248 offers better than 3%
initial accuracy, and constant ground current (typically 100
A)
over load.
The MIC5248 also works with low-ESR ceramic capacitors,
reducing the amount of board space necessary for power
applications, critical in handheld wireless devices.
Key features include current limit, thermal shutdown, a push-
pull output for faster transient response, and an active clamp
to speed up device turnoff. Available in the IttyBittyTM SOT-23-5
package, the MIC5248 is a fixed 1.2V regulator.
MIC5248
Micrel
November 2002
3
MIC5248
Electrical Characteristics
V
IN
= 2.7V, V
EN
= V
IN;
I
OUT
= 100
A; T
J
= 25
C, bold values indicate 40
C
T
J
+125
C; unless noted.
Symbol
Parameter
Conditions
Min
Typical
Max
Units
V
O
Output Voltage Accuracy
I
OUT
= 100
A
3
3
%
4
4
%
V
LNR
Line Regulation
V
IN
= 2.7V to 6V
0.3
0
0.3
%/V
V
LDR
Load Regulation
I
OUT
= 0.1mA to 150mA, Note 4
4.0
5.0
%
I
Q
Quiescent Current
V
EN
0.4V (shutdown)
0.45
1
A
I
GND
Ground Pin Current, Note 5
I
OUT
= 0mA; V
IN
= 6.0V
100
150
A
I
OUT
= 150mA; V
IN
= 6.0V
100
150
A
PSRR
Power Supply Rejection
f = 120Hz, C
OUT
= 4.7
F, I
OUT
= 150mA
60
dB
I
LIM
Current Limit
V
OUT
= 0V
160
350
mA
Enable Input
V
IL
Enable Input Logic-Low Voltage
V
IN
= 5.5V, regulator shutdown
0.4
V
V
IH
Enable Input Logic-High Voltage
V
IN
= 5.5V, regulator enabled
1.6
V
I
EN
Enable Input Current
V
IL
0.4V; V
IN
= 5.5V
0.01
A
V
IH
1.6V; V
IN
= 5.5V
0.01
A
Thermal Protection
Thermal Shutdown Temperature
150
C
Thermal Shutdown Hysteresis
10
C
Power Good, Note 6
V
PG
Low Threshold
% of V
OUT
(PG ON)
89.5
%
High Threshold
% of V
OUT
(PG OFF)
96.5
%
V
OL
PG Output Logic-Low Voltage
I
L
= 100
A, fault condition
0.02
0.1
V
I
PG
Power Good Leakage Current
power good off, V
PG
= 5.5V
0.01
A
V
PG
Delay
Delay Time to Power Good
See "Timing Diagram"
1
5
ms
Note 1.
Exceeding the absolute maximum rating may damage the device.
Note 2.
The device is not guaranteed to function outside its operating rating.
Note 3.
Devices are ESD sensitive. Handling precautions recommended.
Note 4.
Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load
range from 0.1mA to 150mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification.
Note 5.
Ground pin current is the regulator quiescent current. The total current drawn from the supply is the sum of the load current plus the ground
pin current.
Note 6.
The power good is a function of the output voltage being 5% low and the detection of one of the following: overcurrent, over-temperature or
dropout. See "Applications Information" section for additional information.
Absolute Maximum Ratings
(Note 1)
Supply Input Voltage (V
IN
) .................................. 0V to +7V
Enable Input Voltage (V
EN
) .................................. 0V to V
IN
Flag Output Voltage (V
PG
) ................................... 0V to V
IN
Junction Temperature (T
J
) ...................................... +150
C
Storage Temperature ............................... 65
C to +150
C
Lead Temperature (soldering, 5 sec.) ....................... 260
C
ESD, Note 3
Operating Ratings
(Note 2)
Input Voltage (V
IN
) ......................................... +2.7V to +6V
Enable Input Voltage (V
EN
) .................................. 0V to V
IN
Flag Output Voltage (V
PG
) ................................... 0V to V
IN
Junction Temperature (T
J
) ....................... 40
C to +125
C
Thermal Resistance
SOT-23
(
JA
) ...................................................... 235
C/W
MIC5248
Micrel
November 2002
5
MIC5248
95
97
99
101
103
105
107
109
111
113
2.5 3 3.5 4 4.5 5 5.5 6 6.5
GROUND CURRENT (
A)
INPUT VOLTAGE (V)
Ground Current vs.
Input Voltage
I
OUT
= 100
A
I
OUT
= 150mA
98.2
98.4
98.6
98.8
99
99.2
99.4
0
20 40 60 80 100 120 140 160
GROUND CURRENT (
A)
OUTPUT CURRENT (mA)
Ground Current vs.
Output Current
V
IN
= 3.3V
85
90
95
100
105
110
-40 -20 0 20 40 60 80 100120140
GROUND CURRENT (
A)
TEMPERATURE (
C)
Ground Current vs.
Temperature
I
OUT
= 100
A
I
OUT
= 150mA
260
270
280
290
300
310
320
330
340
350
360
2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1
SHORT CIRCUIT CURRENT (mA)
INPUT VOLTAGE (V)
Short Circuit Current
vs. Input Voltage
260
270
280
290
300
310
320
-40 -20 0 20 40 60 80 100120140
SHORT CIRCUIT CURRENT (mA)
TEMPERATURE (
C)
Short Circuit Current
vs. Temperature
V
IN
= 3.3V
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1
POWER GOOD DELAY (ms)
INPUT VOLTAGE (V)
Power Good Delay
vs. Input Voltage
I
OUT
= 100
A
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
-40 -20 0 20 40 60 80 100120140
POWER GOOD DELAY (ms)
TEMPERATURE (
C)
Power Good Delay
vs. Temperature
V
IN
= 3.3V
0
0.5
1
1.5
2
2.5
3
3.5
0.001
0.01
0.1
1
10
100
1000
10000
POWER GOOD (V)
PULL-UP RESISTOR (k
)
Power Good Pull-up Resistor
vs. Power Good
Power Good
Power Fail
1.17
1.175
1.18
1.185
1.19
1.195
2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Output Voltage
vs. Input Voltage
I
OUT
= 100
A
I
OUT
= 150mA
Typical Characteristics
1.16
1.165
1.17
1.175
1.18
1.185
1.19
1.195
0
20 40 60 80 100 120 140 160
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
Output Voltage vs.
Output Current
V
IN
= 3.3V
1.18
1.185
1.19
1.195
1.2
1.205
-40 -20 0 20 40 60 80 100120140
OUTPUT VOLTAGE (V)
TEMPERATURE (
C)
Output Voltage vs.
Temperature
I
OUT
= 100
A
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1
ENABLE VOLTAGE (V)
INPUT VOLTAGE (V)
Enable Voltage vs.
Input Voltage
I
OUT
= 100
A
PDF 
ZIP
