MIC5249_12 Datasheet, PDF (1/7 Pages) Micrel Semiconductor – 300mA μCap LDO with Programmable Power-On Reset Delay

MIC5249
300mA µCap LDO with
Programmable Power-On Reset Delay
General Description
The MIC5249 is an efficient, precise 300mA CMOS
voltage regulator with power on reset (POR) delay which
can be implemented via an external capacitor. It offers 1%
initial accuracy, extremely low dropout voltage (typically
400mV @ 300mA), and low ground current (typically
85mA) over load.
Designed specifically for noise-critical applications in hand-
held or battery-powered devices, the MIC5249 comes
equipped with a noise reduction feature to filter the output
noise via an external capacitor. Other features of the
MIC5249 include a logic-compatible enable pin, current
limit, thermal shutdown, ultra-fast transient response, and
an active clamp to speed up device turnoff.
The MIC5249 also works with low-ESR ceramic
capacitors, reducing the amount of board space necessary
for power applications, critical in hand-held wireless
devices.
The MIC5249 is available in the MSOP-8 package.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
• 300mA output current
• High PSRR: 65dB@120Hz
• Stable with ceramic output capacitor
• Power-on-Reset (POR) output with adjustable delay
time
• High output accuracy:
− ±1.0% initial accuracy
− ±3.0% over temperature
• Low dropout voltage of 340mV @ 300mA
• Low quiescent current: 85µA
• Zero current shutdown mode
• Thermal-shutdown and current-limit protection
• Tiny MSOP-8 package
Applications
• Cellular phones
• PDAs
• Fiber optic modules
Typical Application
Ultra-Low Noise Application
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
March 2012
1
M9999-030812