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www.semtech.com
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 600A.
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
1F capacitor on the output for a minimum number of
external components.
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Battery Powered Systems
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Cellular Telephones
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Cordless Telephones
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Pagers
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Personal Digital Assistants
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Portable Instrumentation
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Cameras
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Portable Consumer Equipment
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PCMCIA Cards
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Ultra low dropout voltage - 100mV @ 50mA
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Guaranteed 50mA output current
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Low ground pin current at all loads
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<1A quiescent current in shutdown
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Wide input supply voltage range 2.5V to 16V
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Wide output voltage range
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Excellent line regulation
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Industrial temperature range
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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) C
IN
is needed if the device is far from the supplys filter capacitors, or for operation from a battery. A value of 1F
or greater should be used. C
IN
may be a tantalum or aluminum electrolytic capacitor.
(2) C
O
should be a 1F 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.