MIC5239
Micrel
MIC5239
Low Quiescent Current 500mA
µ
Cap LDO Regulator
Advance Information
General Description
The MIC5239 is a low quiescent current,
µCap
low-dropout
regulator. With a maximum operating input voltage of 30V
and a quiescent current of 23µA, it is ideal for supplying keep-
alive power in systems with high-voltage batteries.
Capable of 500mA output, the MIC5239 has a dropout
voltage of only 350mV. It can provide high output current for
applications such as USB.
As a
µCap
LDO, the MIC5239 is stable with either a ceramic
or a tantalum output capacitor. It only requires a 3.3µF output
capacitor for stability.
The MIC5239 includes a logic compatible enable input and an
undervoltage error flag indicator. Other features of the
MIC5239 include thermal shutdown, current-limit, overvolt-
age shutdown, load-dump protection, reverse leakage pro-
tections, and reverse battery protection.
Available in the thermally enhanced SOIC-8, MSOP-8 and
SOT-223, the MIC5239 comes in fixed 3.0V and adjustable
voltages. For other output voltages, contact Micrel.
Features
•
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Ultra-low quiescent current (I
Q
= 23µA @I
O
= 100µA)
Continuious 500mA output current
Wide input range: 2.3V to 30V
Low dropout voltage:
350mV @500mA;
±1.0%
initial output accuracy
Stable with ceramic or tantalum output capacitor
Logic compatible enable input
Low output voltage error flag indicator
Overcurrent protection
Thermal shutdown
Reverse-leakage protection
Reverse-battery protection
High-power SOIC-8, MSOP-8 and SOT-223 packages
Applications
• USB power supply
• Keep-alive supply in notebook and portable personal
computers
• Logic supply from high-voltage batteries
• Automotive electronics
• Battery-powered systems
Typical Application
40
V
IN
30V
MIC5239
IN
OUT
EN
FLG
GND
GROUND CURRENT (µA)
35
30
25
20
15
10
4
V
OUT
3.0V/100µA
I
GND
= 23µA
I
OUT
= 1mA
I
OUT
= 100µA
I
OUT
= 10µA
9
14
19
24
INPUT VOLTAGE (V)
29
Regulator with Low I
O
and Low I
Q
Ground Current vs. Input Voltage
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
January 2002
1
MIC5239