LMP8640/LMP8640HV Precision High Voltage Current Sense Amplifier
September 7, 2010
LMP8640/LMP8640HV
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
A
= 25°C
■
High common-mode voltage range
-2V to 42V
—
LMP8640
LMP8640HV
-2V to 76V
—
2.7V to 12V
■
Supply voltage range
20V/V; 50V/V; 100V/V
■
Gain options
0.25%
■
Max gain error
900µV
■
Low offset voltage
Input bias current
13 μA
■
PSRR
85 dB
■
103 dB
■
CMRR (2.1V to 42V)
-40°C to 125°C
■
Temperature range
■
6-Pin TSOT Package
Applications
■
■
■
■
■
■
High-side current sense
Vehicle current measurement
Motor controls
Battery monitoring
Remote sensing
Power management
Typical Application
30071462
LMP™ is a trademark of National Semiconductor Corporation.
© 2010 National Semiconductor Corporation
300714
www.national.com
NSC [ NATIONAL SEMICONDUCTOR ]
