LMP8278Q Datasheet, PDF (1/17 Pages) Texas Instruments – High Common Mode, 14 x Gain, Precision Current Sensing Amplifier

LMP8278Q
February 9, 2012
High Common Mode, 14 x Gain, Precision Current Sensing
Amplifier
General Description
The LMP8278 is a fixed 14x gain precision current sense
amplifier. The part amplifies and filters small differential
signals in the presence of high common mode voltages. The
part operates from a single 5V supply voltage. With an input
common mode voltage range from -2V to +28V the gain is
very precise (±0.5%). The part can handle common mode
voltages in the range -2V to +40V with relaxed specifications.
The LMP8278 is a member of the Linear Monolithic Precision
(LMP^®) family and is ideal for unidirectional current sensing
applications. The parameter values that are shown in the
Electrical Characteristics table are 100% tested and all bold
values are also 100% tested over temperature, unless other-
wise noted.
The part has a precise gain of 14x 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 7x 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 LMP8278Q 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
■ ^TCVos
±15μV/°C max
■ ^CMRR
80 dB min
■ ^{Input offset voltage}
±2 mV max
■ ^CMVR
−2V to 40V
■ ^{Operating ambient temperature range −40°C to 125°C}
■ Single supply operation
■ Min / Max limits 100% tested unless otherwise noted
■ ^{LMP8278Q available in Automotive AEC-Q100 Grade 1}
qualified version
Applications
■ ^{High side and low side driver configuration current sensing}
■ ^{Automotive fuel injection control}
■ ^{Transmission control}
■ ^{Power steering}
■ ^{Battery management systems}
Typical Applications
LMP^® is a registered trademark of National Semiconductor Corporation.
© 2012 Texas Instruments Incorporated 300881 SNAS575
30088101
www.ti.com