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

6 Supply Level for Current Output

Current output stage has unipolar supply VCCI. OPA2990S can be powered by a supply voltage down to 2.7V. Assuming maximum output can reach Vout (max)=VCCI-1.5V. The maximum load for current output is RLoad(max)=Vout (max)/ 20mA. These equations can give you the minimum supply required for specific maximum load target. For RLoad=600Ω which is a common value, the minimum supply level is around 13.5V. to drive a 1kOhm load though, you need 22V instead. If 20% over current (24mA) is going to be used, then 20% higher voltage is needed.