Sense resistors R1 converts a current into a voltage. This voltage is buffered (gain of 1) from the input to the output in this amplifier. V1 tests the circuit for response to common mode variation. A simulation will show that the output voltage variation due to the common mode voltage V1 is very small.
The LT1997-3 combines a precision operational amplifier with highly-matched resistors to form a one-chip solution for accurately amplifying voltages. Gains from –13 to +14 with accuracy of 0.006% (60ppm) can be achieved using no external components. The LT1997-3 is particularly well suited for use as a difference amplifier, where the excellent resistor matching results in a common mode rejection ratio of greater than 91dB.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.