SBOA441 October   2020 OPA192 , OPA2192

 

  1.   Design Goals
  2.   Design Description
  3.   Design Notes
  4.   Design Steps
  5.   Design Simulations
  6.   DC Simulation Results
  7.   Design References
  8.   Design Featured Op Amp
  9.   Design Alternate Op Amp

Design Simulations

A design goal of ±25mA of output current from an input voltage difference of ±5V and a 500-Ω load results in a Vload value of ±12.5V, assuming a Vtermination voltage of 0V. The remaining ±2.5 volts must accommodate the output swing-to-rail of the selected op amp as well as the maximum voltage across the shunt. For these reasons a 20-Ω shunt resistor and a gain of 1/10 (V/V) was chosen. This Vload value is also within the voltage compliance range of the buffer.

A DC input voltage difference sweep is simulated with a fixed Vn input of 0V and the Vp input swept from –5V to 5V. As the following image shows, the input common-mode range, output swing-to-rail, and output current are within the specifications of the selected op amps. The configuration and results follow.