下载
User's Guide
SNOA537A–December 2008–Revised April 2013
AN–1932 LMP2021MAEVAL - Bridge Sensor
Instrumentation Amplifier Evaluation Board
1 Introduction
The LMP2021MAEVAL instrumentation amplifier evaluation board is configured as a differential-in,
differential-out amplifier using the LMP2021. Also included is a precision reference and buffer to drive a
bridge sensor. The board is set up to be used with the ADC141S626 evaluation board (part number:
ADC141S626EB).
2 Power
J3 Connect to the positive supply.
J4 Connect to ground.
J5 If using dual supplies connect to the negative supply. If using a single supply short J5 to ground.
J7 Pin 1 of J2 can be used to power the ADC141S626EB evaluation board, which requires +5 V. If J3 is +5 V, JP3 can be
shorted to provide +5 V to the ADC141S626EB evaluation board. If J3 is not +5 V, leave JP3 open and connect +5 V to J7.
3 Input Signal and Bridge Excitation
J1 is used to power the bridge sensor and input the signal from the bridge to the amplifier. The LM4120
(U4) provides a precision +5 V reference. This is buffered by the LMP7741 (U5) and supplied on pin 1 of
J1 to power the bridge sensor. The bottom of the bridge sensor can be connected to pin 2, which is
connected to ground. The outputs of the bridge sensor can be connected to pins 3 and 5 of J1.
4 Output Signal
The output of the amplifier is available on pins 3 and 5 of J2. This connector is pin-to-pin compatible with
the input connector of the ADC141S626EB evaluation board.
5 Amplifier Gain
The gain of the amplifier is set using R1, R10, R11, and R12. If R11 = R12, the gain of the amplifier is 1 +
(2R11)/(R1||R10).
All trademarks are the property of their respective owners.
1
SNOA537A–December 2008–Revised April 2013 AN–1932 LMP2021MAEVAL - Bridge Sensor Instrumentation Amplifier
Evaluation Board
Submit Documentation Feedback
Copyright © 2008–2013, Texas Instruments Incorporated
