LMP8602 Datasheet, PDF (1/24 Pages) National Semiconductor (TI) – 60V Common Mode, Fixed Gain, Bidirectional Precision Current Sensing Amplifier

LMP8602/LMP8603
July 17, 2009
60V Common Mode, Fixed Gain, Bidirectional Precision
Current Sensing Amplifier
General Description
The LMP8602 and LMP8603 are fixed gain precision ampli-
fiers. The parts will amplify and filter small differential signals
in the presence of high common mode voltages. The input
common mode voltage range is –22V to +60V when operating
from a single 5V supply. With a 3.3V supply, the input com-
mon mode voltage range is from –4V to +27V. The LMP8602
and LMP8603 are members of the Linear Monolithic Precision
(LMP^®) family and are ideal parts for unidirectional and bidi-
rectional current sensing applications. All parameter values
of the parts that are shown in the tables are 100% tested and
all bold values are also 100% tested over temperature.
The parts have a precise gain of 50x for the LMP8602 and
100x for the LMP8603, which are adequate in most targeted
applications to drive an ADC to its full scale value. The fixed
gain is achieved in two separate stages, a preamplifier with a
gain of 10x and an output stage buffer amplifier with a gain of
5x for the LMP8602 and 10x for the LMP8603. The connection
between the two stages of the signal path is brought out on
two pins to enable the possibility 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 applications 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 LMP8602 and LMP8603 are available in a 8–Pin SOIC
package and in a 8–Pin MSOP package.
Features
Unless otherwise noted, typical values at T_A = 25°C,
V_S = 5.0V, Gain = 50x (LMP8602), Gain = 100x (LMP8603)
■ ^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
■ 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 300834
30083401
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