LMP8645 Datasheet, PDF (1/16 Pages) National Semiconductor (TI) – Precision High Voltage Current Sense Amplifier

LMP8645/LMP8645HV
July 1, 2010
Precision High Voltage Current Sense Amplifier
General Description
The LMP8645 and the LMP8645HV 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 LMP8645 accepts input signals with common mode volt-
age range from -2V to 42V, while the LMP8645HV accepts
input signal with common mode voltage range from -2V to
76V. The LMP8645 and LMP8645HV have adjustable gain
for applications where supply current and high common mode
voltage are the determining factors. The gain is configured
with a single resistor, providing a high level of flexibility, the
accuracy could be as low as 2% (max) including the gain set-
ting resistor. 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 LMP8645 is an ideal choice for industrial, au-
tomotive and consumer applications, and it is available in
TSOT-6 package.
Features
Typical values, T_A = 25°C
■ ^{High common-mode voltage range}
— LMP8645
-2V to 42V
— LMP8645HV
-2V to 76V
■ ^{Supply voltage range}
2.7V to 12V
■ ^{Gain configurable with a single resistor}
■ ^{Max variable gain accuracy (with external resistor) 2.0%}
■ ^{Transconductance}
200 μA/V
■ ^{Low offset voltage}
1 mV
■ ^{Input bias}
12 μA
■ ^PSRR
90 dB
■ ^CMRR
95 dB
■ ^{Temperature range}
−40°C to 125°C
■ ^{6-Pin TSOT Package}
Applications
■ ^{High-side current sense}
■ ^{Vehicle current measurement}
■ ^{Motor controls}
■ ^{Battery monitoring}
■ ^{Remote sensing}
■ ^{Power management}
Typical Application
LMP™ is a trademark of National Semiconductor Corporation.
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