LMP8601 Datasheet, PDF (1/22 Pages) National Semiconductor (TI) – 60V Common Mode, Bidirectional Precision Current Sensing Amplifier

LMP8601/LMP8601Q
July 16, 2009
60V Common Mode, Bidirectional Precision Current
Sensing Amplifier
General Description
The LMP8601 and LMP8601Q are fixed 20x gain precision
amplifiers. The part will amplify and filter small differential sig-
nals in the presence of high common mode voltages. The
input common mode voltage range is –22V to +60V when op-
erating from a single 5V supply. With 3.3V supply, the input
common mode voltage range is from –4V to +27V. The
LMP8601 and LMP8601Q are members of the Linear Mono-
lithic Precision (LMP^®) family and are ideal parts for unidirec-
tional and bidirectional current sensing applications. All
parameter values of the part that are shown in the tables are
100% tested and all bold values are also 100% tested over
temperature.
The part has a precise gain of 20x which is adequate in most
targeted applications to drive an ADC to its full scale value.
The fixed gain is achieved in two separate stages, a pream-
plifier with a gain of 10x and an output stage buffer amplifier
with a gain of 2x. The connection between the two stages of
the signal path is brought out on two pins to enable the pos-
sibility to create an additional filter network around the output
buffer amplifier. These pins can also be used for alternative
configurations with different gain as described in the applica-
tions section .
The mid-rail offset adjustment pin enables the user to use
these devices for bidirectional single supply voltage current
sensing. The output signal is bidirectional and mid-rail refer-
enced when this pin is connected to the positive supply rail.
With the offset pin connected to ground, the output signal is
unidirectional and ground-referenced .
The LMP8601Q incorporates enhanced manufacturing and
support processes for the automotive market, including defect
detection methodologies. Reliability qualification is compliant
with the requirements and temperature grades defined in the
AEC Q100 standard.
Features
Unless otherwise noted, typical values at T_A = 25°C,
V_S = 5.0V, Gain = 20x
■ ^TCV_OS
■ ^CMRR
10μV/°C max
90 dB min
■ ^{Input offset voltage}
1 mV max
■ ^{CMVR at V}_S ^{= 3.3V}
■ ^{CMVR at V}_S ^{= 5.0V}
■ ^{Operating ambient temperature range}
−4V to 27V
−22V to 60V
−40°C to 125°C
■ ^{LMP8601Q available in Automotive AEC-Q100 Grade 1}
qualified version
■ Single supply bidirectional operation
■ All Min / Max limits 100% tested
Applications
■ ^{High side and low side driver configuration current sensing}
■ ^{Bidirectional current measurement}
■ ^{Current loop to voltage conversion}
■ ^{Automotive fuel injection control}
■ ^{Transmission control}
■ ^{Power steering}
■ ^{Battery management systems}
Typical Applications
LMP™ is a trademark of National Semiconductor Corporation.
© 2009 National Semiconductor Corporation 201571
20157101
www.national.com