MIC5255 Datasheet, PDF (1/11 Pages) Micrel Semiconductor – 150mA Low Noise UCap CMOS LDO

MIC5255
Micrel
MIC5255
150mA Low Noise µCap CMOS LDO
General Description
The MIC5255 is an efficient, precise CMOS voltage regulator
optimized for ultra-low-noise applications. It offers 1% initial
accuracy, extremely-low dropout voltage (135mV at 150mA)
and low ground current (typically 90µA). The MIC5255 pro-
vides a very-low-noise output, ideal for RF applications
where a clean voltage source is required. A noise bypass pin
is also available for further reduction of output noise.
Designed specifically for handheld and battery-powered de-
vices, the MIC5255 provides a TTL-logic-compatible enable
pin. When disabled, power consumption drops nearly to zero.
The MIC5255 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, faster
transient response, and an active clamp to speed up device
turn-off. Available in the 6-pin 2mm × 2mm MLF™ package,
the IttyBitty® SOT-23-5 package and the new Thin SOT-23-
5, which offers the same footprint as the standard IttyBitty®
SOT-23-5, but only 1mm tall. The MIC5255 offers a range of
output voltages.
All support documentation can be found on Micrel’s web
site at www.micrel.com.
Features
• Input voltage range: 2.7V to 6.0V
• Thin SOT package: 1mm height SOT-23-5
• Ultra-low output noise: 30µV(rms)
• Stability with ceramic output capacitors
• Ultra-low dropout: 135mV @ 150mA
• High output accuracy:
1.0% initial accuracy
2.0% over temperature
• Low quiescent current: 90µA
• Tight load and line regulation
• TTL-Logic-controlled enable input
• “Zero” off-mode current
• Thermal shutdown and current limit protection
Applications
• Cellular phones and pagers
• Cellular accessories
• Battery-powered equipment
• Laptop, notebook, and palmtop computers
• Consumer/personal electronics
Typical Application
C_IN = 1.0µF ^VIN
MIC5255-x.xBM5
1
5
V_OUT
V_IN
Ceramic
Enable
Shutdown
ENABLE
2
SHUTDOWN
EN
3
4
C_OUT = 1.0µF
Ceramic
EN
EN (pin 3) may be
connected directly
to IN (pin 1).
C_BYP = 0.01µF
MIC5255-x.xBML
1
6
2
5
3
4
C_BYP
(optional)
Ultra-Low-Noise Regulator Application
V_OUT
C_OUT
IttyBitty is a registered trademark of Micrel, Inc.
MicroLeadFrame and MLF are trademarks of Amkor Technology.
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone]• http://www.micrel.com
August, 2004
1
M0385-080204