SBOA594 August   2024 OPA2990

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
  5. 2 Circuit Description
  6. 3 Supporting Multiple Output Ranges
  7. 4 Resistor Sizing, M2 Selection, and Other Design Considerations
  8. 5 Mode and Range Control
  9. 6 Supply Level for Current Output
  10. 7 Supply Levels for Voltage Output
  11. 8 Protection Features
  12. 9 Measurement Results
  13. 10Power Consumption
  14. 11Error Monte-Carlo Analysis
  15. 12Rise and Fall Times
  16. 13Building Multi-Channel Output
  17. 14Summary
  18. 15References

5 Mode and Range Control

Range control switches S1, and S2 can be implemented using 1:1 SPST switch pair, which is powered by 2.7V to 5V which is typically available for data converters. TMUX1511 is a cost-effective choice here for 4 switches, for example, can support two combined V/I channels. TMUX1511 can be controlled with 1.8V volt logic.

The shutdown for the OPA2990S opamps are referred to the negative supply of the opamp, with disable threshold at 0.8V. for current path which is referred to the GND, a logic signal 1.8V or higher can be used to disable U1 and U2. For U3, and U4 though, a level shifter is required. A simple P MOSFET level shifter can be used.