
LP2951
1998 SEMTECH CORP.
150mA ADJUSTABLE
VOLTAGE REGULATOR
March 17, 1998
652 MITCHELL ROAD NEWBURY PARK CA 91320
1
DESCRIPTION
The LP2951 series of low power voltage regulators
have low quiescent current and low dropout voltage.
The quiescent current increases minimally during
dropout conditions thereby extending battery life.
Available in the 8 lead SOIC package, the LP2951 se-
ries includes features such as shutdown and low out-
put voltage detect (typically due to low battery condi-
tions). This function may also be used as a power on
reset function when triggered by CMOS or TTL inputs.
The circuit can be used as a fixed voltage 5 volt (3.3
volt for LP2951CM-3.3) regulator or adjusted between
1.24 volts and 29 volts using external resistor pairs.
FEATURES
= Guaranteed 150mA current
= Adjustable output voltage - 1.24V to 29V
= Accurate 5V or 3.3V output @ 100mA
= Low dropout voltage - 350-400mV @ 100mA
= Regulator or reference functions
= Direct replacement for LP2951C, MIC2951-03,
AS2951C
TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com
PIN CONFIGURATION
BLOCK DIAGRAM
ABSOLUTE MAXIMUM RATINGS
Parameter
Symbol
Maximum
Units
Supply Voltage
V
IN
-0.3 to 30
V
Shutdown Input
Voltage
-0.3 to 30
V
Error Comp. Output
Voltage
-0.3 to 30
V
Power Dissipation
P
D
Internally
Limited
W
Thermal Resistance
Junction to Ambient
θ
JA
175
°C/W
Operating Junction
Temperature Range
T
J
-40 to 125
°C
Storage
Temperature Range
T
STG
-65 to 150
°C
Lead Temperature
(Soldering) 5 Sec
T
LEAD
260
°C
APPLICATIONS
= Microcontroller supplies
= Linear regulators
= Adjustable Supplies
= Switching power supplies - post-regulation
= Portable modems
= Battery powered systems
= Cellular telephones
= Voltage references
Notes:
(1) Where -X.X denotes voltage options. Available
voltages are: 3.3V (-3.3) and 5V (leave blank).
(2) Add suffix ‘TR’ for tape and reel.
ORDERING INFORMATION
DEVICE
(1)(2)
OUTPUT
PACKAGE
LP2951CM-X.X
ADJ
SO-8