LMP8272, LMP8277

High Common Mode, Gain of 14, Precision Voltage

Difference Amplifiers

General Description

fiers with a -2V to 27V input common mode voltage range

and a supply voltage range of 4.5V to 5.5V. The LMP8272,

LMP8277 are precision amplifiers which will detect, amplify

and filter small differential signals in the presence of high

common mode voltages. The gain is fixed at 14 and is

adequate to drive an ADC to full scale in most cases. This

fixed gain is achieved in two separate stages, a pre-amplifier

with gain of +7 and a second stage amplifier with a gain of

+2. The internal signal path between these two stages is

brought out on two pins that provide a connection for a filter

network.

The LMP8272, LMP8277 will function with reduced specifi-

cations over the extended common mode input voltage

range of -5 to 36 Volts. This feature makes the device

suitable for applications with load dump in automotive sys-

tems.

Features

n

Typical Values, TA = 25˚C

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Input Offset Voltage

1mV max

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TCVos (LMP8272)

15µV/˚C max

n

TCVos (LMP8277)

30µV/˚C max

n

CMRR

80dB Min

n

Extended CMVR

-5V to 36V

n

Output Voltage Swing

Rail to Rail

n

Bandwidth

80KHz

n

Operating Temperature Range (Ambient) -40˚C to 125˚C

n

Operating Temperature Range (bare die) -40˚C to 150˚C

n

Supply Voltage

4.5V to 5.5V

n

Supply Current

1mA

Applications

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Fuel Injection Control

n

Low Side Driver Configuration Current Sensing

n

Power Management Systems

Typical Application

Typical Application: Low side Current Sensing

20130901

PRELIMINARY

January 2005

© 2005 National Semiconductor Corporation

DS201309

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