MIC5239
Low Quiescent Current 500mA µCap
LDO Regulator
General Description
Features
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.
• Ultra-low quiescent current (IQ = 23µA @IO = 100µA)
• Continuous 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
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, reverse-leakage protection, and reverse-
battery protection.
• Thermal shutdown
• Reverse-leakage protection
• Reverse-battery protection
• High-power SOIC-8, MSOP-8 and SOT-223 packages
Available in the thermally enhanced SOIC-8, MSOP-8 and
SOT-223, the MIC5239 comes in fixed 1.5V, 1.8V, 2.5V,
3.0V, 3.3V and 5.0V, and adjustable voltages. For other
output voltages, contact Micrel.
Applications
• USB power supply
• Keep-alive supply in notebook and portable personal
computers
All support documentation can be found on Micrel’s web
site at: www.micrel.com.
• Logic supply from high voltage batteries
• Automotive electronics
• Battery-powered systems
___________________________________________________________________________________________________________
Typical Application
40
35
I
OUT = 1mA
MIC5239
IOUT = 100µA
30
25
20
15
10
VIN
30V
VOUT
3.0V/100µA
IN
OUT
IGND = 23µA
EN
FLG
GND
I
OUT = 10µA
9
14
24
4
19
29
Regulator with Low IO and Low IQ
Ground Current vs. Input Voltage
MLF and MicroLeadFrame is a registered trademark of Amkor Technologies
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
M9999-121007
December 2007