POWER MANAGEMENT
Description
The SC2982 is a 50mA ultra low dropout linear
regulator with a built in CMOS/TTL logic level enable
switch. It is designed specifically for battery powered
applications where low quiescent current and low
dropout are critical for battery longevity.
50mA Ultra Low Dropout, Low
Noise Micropower Linear Regulator
PRELIMINARY
Features
Ultra low dropout voltage - 100mV @ 50mA
Guaranteed 50mA output current
Low ground pin current at all loads
<1碌A(chǔ) quiescent current in shutdown
Wide input supply voltage range 2.5V to 16V
Wide output voltage range
Excellent line regulation
Industrial temperature range
Surface mount packaging (5 pin SOT-23)
SC2982
u
u
u
u
u
u
The SC2982 uses a Semtech proprietary internal PNP
device for the pass element, providing a low dropout
u
voltage of 100mV at a load of 50mA, while maintaining a
u
u
ground pin current of 600碌A(chǔ).
The output noise is reduced by placing a 10nF capacitor
on pin 4 (bypass).
Applications
Battery Powered Systems
Cellular Telephones
Cordless Telephones
Pagers
Personal Digital Assistants
Portable Instrumentation
Cameras
Portable Consumer Equipment
PCMCIA Cards
u
u
Each device contains a bandgap reference, error
u
amplifier, PNP pass element, thermal and current
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limiting circuitry and resistor divider network for setting
u
output voltage.
u
The SC2982 is packaged in a 5 pin SOT-23 surface mount
u
package for a very small footprint and requires only a
u
1碌F capacitor on the output for a minimum number of
u
external components.
Typical Application Circuit
U1 SC2982
1
VIN
2
3
EN
+
C
IN
1uF
VIN
GND
EN
BYP
4
Co
1uF
VO
5
VO
+
C
BYP
10nF
Notes:
(1) C
IN
is needed if the device is far from the supply聮s filter capacitors, or for operation from a battery. A value of 1碌F
or greater should be used. C
IN
may be a tantalum or aluminum electrolytic capacitor.
(2) C
O
should be a 1碌F or greater tantalum or aluminum electrolytic capacitor. Larger value capacitors will improve
the overall transient response. Due to their very low ESR, ceramic capacitors should not be used.
(3) C
BYP
should be placed as close as possible to pin 4 and ground. A 10nF ceramic capacitor is recommended.
(4) EN should be tied to VIN if the shutdown feature is not required. Maximum EN voltage = VIN.
Revision 1, January 2001
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www.semtech.com
SEMTECH
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