LMP8640/LMP8640HV

September 7, 2010

Precision High Voltage Current Sense Amplifier

General Description

The LMP8640 and the LMP8640HV are precision current

sense amplifiers that detect small differential voltages across

a sense resistor in the presence of high input common mode

voltages with a supply voltage range from 2.7V to 12V.

The LMP8640 accepts input signals with common mode volt-

age range from -2V to 42V, while the LMP8640HV accepts

input signal with common mode voltage range from -2V to

76V. The LMP8640 and LMP8640HV have fixed gain for ap-

plications that demand accuracy over temperature. The

LMP8640 and LMP8640HV come out with three different

fixed gains 20V/V, 50V/V, 100V/V ensuring a gain accuracy

as low as 0.25%. The output is buffered in order to provide

low output impedance. This high side current sense amplifier

is ideal for sensing and monitoring currents in DC or battery

powered systems, excellent AC and DC specifications over

temperature, and keeps errors in the current sense loop to a

minimum. The LMP8640 and LMP8640HV are ideal choice

for industrial, automotive and consumer applications, and it is

available in TSOT-6 package.

Features

Typical values, T

— LMP8640

-2V to 42V

— LMP8640HV

-2V to 76V

2.7V to 12V

20V/V; 50V/V; 100V/V

0.25%

900µV

13 μA

85 dB

103 dB

-40°C to 125°C

Applications

Typical Application

30071462

LMP™ is a trademark of National Semiconductor Corporation.

© 2010 National Semiconductor Corporation

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