LP2951CM-3.3.TR - Semtech

LP2951

150mA ADJUSTABLE

VOLTAGE REGULATOR

March 17, 1998

652 MITCHELL ROAD NEWBURY PARK CA 91320

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 VIN -0.3 to 30 V

Shutdown Input

Voltage -0.3 to 30 V

Error Comp. Output

Voltage -0.3 to 30 V

Power Dissipation PDInternally

Limited W

Thermal Resistance

Junction to Ambient θJA 175 °C/W

Operating Junction

Temperature Range TJ-40 to 125 °C

Storage

Temperature Range TSTG -65 to 150 °C

Lead Temperature

(Soldering) 5 Sec TLEAD 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

LP2951

150mA ADJUSTABLE

VOLTAGE REGULATOR

March 17, 1998

652 MITCHELL ROAD NEWBURY PARK CA 91320

NOTE:

(1) Temperature coefficient is defined as the worst case voltage change divided by total temperature range.

ELECTRICAL CHARACTERISTICS

Unless specified, limits are over operating temperature range (TJ = TA), VIN = VOUT(NOM) + 1V, IL=100µA, CL=1µF

Parameter Symbol Conditions Min Typ Max Units

Output Voltage

LP2951CM VOUT TJ = 25°C, IL = 100µA 4.950 5.000 5.050 V

LP2951CM-3.3 3.267 3.300 3.333

Temp Coefficient(1) TC0°C ≤ TJ ≤=70°C 20 120 ppm/°C

Line Regulation REG(LINE) (VO(NOM) + 1V) ≤ VIN=≤=30V 0.1 0.5 %

Load Regulation REG(LOAD) 100µA ≤ IL=≤=100mA 0.1 0.4 %

Dropout Voltage VDIL===100µA 80 150 mV

IL===100mA 380 600

Ground Current IGND IL===100µA 120 160 µA

IL===100mA 814 mA

Dropout Ground Current IGND(D) VIN = (VO(NOM) - 0.5V), IL===100µA 110 250 µA

Current Limit ICL VOUT = 0 200 250 mA

Reference Voltage VREF VREF ≤ VOUT ≤ (VIN - 1V), TJ ==25°C,

100µA ≤ IL=≤=100mA 1.210 1.235 1.260 V

Feedback Bias Current IFB 20 60 nA

Error Comparator

Output High Leakage

Current VOH = 30V 2 µA

Output Low Voltage VIN = (VO(NOM) - 0.5V), IOL = 400µA 150 400 mV

Threshold Voltage Upper 25 60 mV

Lower 75 140

Hysteresis 15 mV

Shutdown Input

Input Logic Voltage VSD Low 0.6 V

High 2.0 V

Input Current ISD VSHUTDOWN = 2.4V 100 µA

VSHUTDOWN = 30V 750

Regulator Shutdown

Output Current IO(SD) VSHUTDOWN ≥ 2V, VIN ≤ 30V,

VOUT = 0, Feedback pin to Tap 20 µA

LP2951

150mA ADJUSTABLE

VOLTAGE REGULATOR

March 17, 1998

652 MITCHELL ROAD NEWBURY PARK CA 91320

OUTLINE DRAWING SO -8

LAND PATTERN SO-8