MIC5247
Micrel
MIC5247
150mA Low-Voltage
µ
Cap Linear Regulator
Preliminary Information
General Description
The MIC5247 is an efficient, precise low voltage CMOS
voltage regulator optimized for ultra-low-noise applications.
The MIC5247 offers better than 1% initial accuracy, and 85µA
constant ground current over load (typically 85µA). The
MIC5247 provides a very low noise output, ideal for RF
applications where quiet voltage sources are required. A
noise bypass pin is also available for further reduction of
output noise.
Designed specifically for hand-held and battery-powered
devices, the MIC5247 provides a logic compatible enable pin.
When disabled, power consumption drops nearly to zero.
The MIC5247 also works with low-ESR ceramic capacitors,
reducing the amount of board space necessary for power
applications, critical in hand-held 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 MIC5247 also offers a range of fixed output
voltages.
Features
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Ultralow noise
Low voltage outputs
Load independent, ultralow ground current: 85µA
150mA output current
Current limiting
Thermal Shutdown
Tight load and line regulation
“Zero” off-mode current
Stability with low-ESR capacitors
Fast transient response
Logic-controlled enable input
Cellular phones and pagers
Cellular accessories
Battery-powered equipment
Laptop, notebook, and palmtop computers
PCMCIA V
CC
and V
PP
regulation/switching
Consumer/personal electronics
SMPS post-regulator/dc-to-dc modules
High-efficiency linear power supplies
Applications
Ordering Information
Part Number
MIC5247-1.5BM5
MIC5247-1.8BM5
MIC5247-2.0BM5
MIC5247-2.4BM5
Marking
LU15
LU18
LU20
LU24
Voltage
1.5V
1.8V
2.0V
2.4V
Junction Temp. Range
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
Package
SOT-23-5
SOT-23-5
SOT-23-5
SOT-23-5
Other voltages available. Contact Micrel for details.
Typical Application
V
IN
MIC5247-x.xBM5
1
2
Enable
Shutdown
3
4
5
V
OUT
C
OUT
EN
EN (pin 3) may be
connected directly
to IN (pin 1).
C
BYP
(optional)
Ultra-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 6, 2000
1
MIC5247
MICREL [ MICREL SEMICONDUCTOR ]
