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SC2982
50mA Ultra Low Dropout, Low
Noise Micropower Linear Regulator
POWER MANAGEMENT PRELIMINARY
Revision 1, January 2001
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.
The SC2982 uses a Semtech proprietary internal PNP
device for the pass element, providing a low dropout
voltage of 100mV at a load of 50mA, while maintaining a
ground pin current of 600µA.
The output noise is reduced by placing a 10nF capacitor
on pin 4 (bypass).
Each device contains a bandgap reference, error
amplifier, PNP pass element, thermal and current
limiting circuitry and resistor divider network for setting
output voltage.
The SC2982 is packaged in a 5 pin SOT-23 surface mount
package for a very small footprint and requires only a
1µF capacitor on the output for a minimum number of
external components.
u Battery Powered Systems
u Cellular Telephones
u Cordless Telephones
u Pagers
u Personal Digital Assistants
u Portable Instrumentation
u Cameras
u Portable Consumer Equipment
u PCMCIA Cards
u Ultra low dropout voltage - 100mV @ 50mA
u Guaranteed 50mA output current
u Low ground pin current at all loads
u <1µA quiescent current in shutdown
u Wide input supply voltage range 2.5V to 16V
u Wide output voltage range
u Excellent line regulation
u Industrial temperature range
u Surface mount packaging (5 pin SOT-23)
EN
VIN VO
+
C
1uF
U1 SC2982
1
2
3 4
5
VIN
GND
EN BYP
VO
+
Co
1uF
C
10nF
IN
BYP
Description Features
Applications
Typical Application Circuit
Notes:
(1) CIN is needed if the device is far from the supplys filter capacitors, or for operation from a battery. A value of 1µF
or greater should be used. CIN may be a tantalum or aluminum electrolytic capacitor.
(2) CO should be a 1µF 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.