MIC5248
Micrel
MIC5248
150mA
µ
Cap CMOS LDO Regulator w/Power Good
Final Information
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 100µA)
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 IttyBitty™ SOT-23-5
package, the MIC5248 is a fixed 1.2V regulator.
Features
•
•
•
•
•
•
•
•
•
•
Power Good indicator
Load independent, ultra-low ground current: 100µA
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
Ordering Information
Part Number
MIC5248-1.2BM5
MIC5248-1.2YM5
Marking
LV12
KV12
Voltage
1.2
1.2
Junction Temp. Range*
–40°C to +125°C
–40°C to +125°C,
Lead-free
Package
SOT-23-5
SOT-23-5
Other voltages available. Contact Micrel for details.
Typical Application
47k
V
IN
MIC5248-x.xBM5
1
2
Enable
Shutdown
3
4
5
V
OUT
C
OUT
PG
EN
EN (pin 3) may be
connected directly
to IN (pin 1).
Low-Noise Regulator Application
IttyBitty is a trademark of Micrel, Inc.
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
November 2002
1
MIC5248
MIC5248
Micrel
Pin Configuration
EN GND IN
3
2
1
EN GND IN
3
2
1
LVxx
4
5
4
KVxx
5
PG
OUT
PG
OUT
MIC5248-x.xBM5
MIC5248-x.xYM5
Pin Description
Pin Number
1
2
3
4
5
Pin Name
IN
GND
EN
PG
OUT
Pin Function
Supply Input
Ground
Enable/Shutdown (Input): CMOS compatible input. Logic high = enable; logic
low = shutdown. Do not leave open.
Power Good Output
Regulator Output
MIC5248
2
November 2002
MIC5248
Micrel
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(θ
JA
) ......................................................235°C/W
Electrical Characteristics
V
IN
= 2.7V, V
EN
= V
IN;
I
OUT
= 100µA; T
J
= 25°C,
bold
values indicate –40°C
≤
T
J
≤
+125°C; unless noted.
Symbol
V
O
∆V
LNR
∆V
LDR
I
Q
I
GND
PSRR
I
LIM
Enable Input
V
IL
V
IH
I
EN
Enable Input Logic-Low Voltage
Enable Input Logic-High Voltage
Enable Input Current
V
IN
= 5.5V, regulator shutdown
V
IN
= 5.5V, regulator enabled
V
IL
≤
0.4V; V
IN
= 5.5V
V
IH
≥
1.6V; V
IN
= 5.5V
Thermal Protection
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
Power Good, Note 6
V
PG
V
OL
I
PG
V
PG
Delay
Note 1.
Note 2.
Note 3.
Note 4.
Note 5.
Note 6.
Parameter
Output Voltage Accuracy
Line Regulation
Load Regulation
Quiescent Current
Ground Pin Current,
Note 5
Conditions
I
OUT
= 100µA
V
IN
= 2.7V to 6V
I
OUT
= 0.1mA to 150mA,
Note 4
V
EN
≤
0.4V (shutdown)
I
OUT
= 0mA; V
IN
= 6.0V
I
OUT
= 150mA; V
IN
= 6.0V
f = 120Hz, C
OUT
= 4.7µF, I
OUT
= 150mA
V
OUT
= 0V
Min
–3
–4
–0.3
Typical
Max
3
4
Units
%
%
%/V
%
µA
µA
µA
dB
mA
0
4.0
0.45
100
100
60
0.3
5.0
1
150
150
Power Supply Rejection
Current Limit
160
350
0.4
1.6
0.01
0.01
V
V
µA
µA
°C
°C
150
10
Low Threshold
High Threshold
PG Output Logic-Low Voltage
Power Good Leakage Current
Delay Time to Power Good
% of V
OUT
(PG ON)
% of V
OUT
(PG OFF)
I
L
= 100µA, fault condition
power good off, V
PG
= 5.5V
See “Timing Diagram”
89.5
96.5
0.02
0.01
1
5
0.1
%
%
V
µA
ms
Exceeding the absolute maximum rating may damage the device.
The device is not guaranteed to function outside its operating rating.
Devices are ESD sensitive. Handling precautions recommended.
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.
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.
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.
November 2002
3
MIC5248
MIC5248
Micrel
Block Diagrams
IN
EN
Reference
Voltage
Startup/
Shutdown
Control
Quickstart
PULL
UP
Thermal
Sensor
FAULT
Error
Amplifier
Current
Amplifier
PULL
DOWN
OUT
Under-
voltage
Lockout
ACTIVE SHUTDOWN
Out of
Regulation
Detection
PG
Overcurrent
Dropout
Detection
Delay
GND
Timing Diagram
V
OUT
96.5%
89.5%
96.5%
Fault Condition
V
EN
Min - Max
1-5ms
1-5ms
V
PG
Indeterminable
when V
EN
low
MIC5248
4
November 2002
MIC5248
Micrel
Typical Characteristics
Ground Current vs.
Input Voltage
113
GROUND CURRENT (µA)
GROUND CURRENT (µA)
111
109
107
105
103
101
99
97
95
2.5 3 3.5 4 4.5 5 5.5 6 6.5
INPUT VOLTAGE (V)
I
OUT
= 150mA
I
OUT
= 100µA
99.4
99.2
99
98.8
98.6
98.4
98.2
0
20 40 60 80 100 120 140 160
OUTPUT CURRENT (mA)
GROUND CURRENT (µA)
V
IN
= 3.3V
Ground Current vs.
Output Current
110
105
100
95
90
Ground Current vs.
Temperature
I
OUT
= 100µA
I
OUT
= 150mA
85
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
Short Circuit Current
vs. Input Voltage
SHORT CIRCUIT CURRENT (mA)
SHORT CIRCUIT CURRENT (mA)
360
350
340
330
320
310
300
290
280
270
260
2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1
INPUT VOLTAGE (V)
320
310
300
290
280
270
Short Circuit Current
vs. Temperature
POWER GOOD DELAY (ms)
V
IN
= 3.3V
2
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
Power Good Delay
vs. Input Voltage
I
OUT
= 100µA
260
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
1.1
1
2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1
INPUT VOLTAGE (V)
Power Good Delay
vs. Temperature
POWER GOOD DELAY (ms)
2
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
V
IN
= 3.3V
POWER GOOD (V)
Power Good Pull-up Resistor
vs. Power Good
3.5
OUTPUT VOLTAGE (V)
1.195
Output Voltage
vs. Input Voltage
I
OUT
= 100µA
3
2.5
2
1.5
1
0.5
0.01
0.1
Power Good
1.19
1.185
1.18
1.175
I
OUT
= 150mA
Power Fail
10000
10
1
1000
100
0.001
0
1.17
2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1
INPUT VOLTAGE (V)
PULL-UP RESISTOR (kΩ)
Output Voltage vs.
Output Current
1.195
OUTPUT VOLTAGE (V)
1.19
OUTPUT VOLTAGE (V)
1.185
1.18
1.175
1.17
1.165
1.16
0
V
IN
= 3.3V
20 40 60 80 100 120 140 160
OUTPUT CURRENT (mA)
1.2
1.195
1.19
1.185
1.205
Output Voltage vs.
Temperature
ENABLE VOLTAGE (V)
Enable Voltage vs.
Input Voltage
1.4
1.3
1.2
1.1
1
0.9
0.8
0.7
I
OUT
= 100µA
I
OUT
= 100µA
1.18
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
0.6
2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1
INPUT VOLTAGE (V)
November 2002
5
MIC5248
微控制器 MCU
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