MIC5245
Micrel
MIC5245
150mA
µ
Cap CMOS LDO Regulator
Preliminary Information
General Description
The MIC5245 is an efficient, precise CMOS voltage regulator
optimized for ultra-low-noise applications. The MIC5245 of-
fers better than 1% initial accuracy, extremely low dropout
voltage (typically 150mV at 150mA) and constant ground
current over load (typically 100µA). The MIC5245 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 MIC5245 provides a TTL logic compatible en-
able pin. When disabled, power consumption drops nearly to
zero.
The MIC5245 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
and power MSO-8 packages, the MIC5245 also offers a
range of fixed output voltages.
Features
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Ultralow dropout—100mV @ 100mA
Ultralow noise—30µV(rms)
Stability with tantalum or ceramic capacitors
Load independent, ultralow ground current
150mA output current
Current limiting
Thermal Shutdown
Tight load and line regulation
“Zero” off-mode current
Fast transient response
TTL-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
MIC5245-2.5BM5
MIC5245-2.7BM5
MIC5245-2.8BM5
MIC5245-2.85BM5
MIC5245-3.0BM5
MIC5245-3.1BM5
MIC5245-3.3BM5
MIC5245-3.3BMM
Marking
LS25
LS27
LS28
LS2J
LS30
LS31
LS33
—
Voltage
2.5V
2.7V
2.8V
2.85V
3.0V
3.1V
3.3V
3.3V
Junction Temp. Range
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–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
SOT-23-5
SOT-23-5
SOT-23-5
MSOP-8
Other voltages available. Contact Micrel for details.
Typical Application
V
IN
MIC5245-x.xBM5
1
2
Enable
Shutdown
3
4
5
V
OUT
C
OUT
ENABLE
SHUTDOWN
MIC5245-3.3MM
1
2
3
4
8
7
6
5
V
IN
V
OUT
EN
EN (pin 3) may be
connected directly
o IN (pin 1).
C
BYP
(optional)
C
BYP
C
OUT
(OPTIONAL)
Ultra-Low-Noise Regulator Application
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
June 2000
1
MIC5245
MICREL [ MICREL SEMICONDUCTOR ]
