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

11 Error Monte-Carlo Analysis

Prototype measurement does not give information about the full extent of the error distribution due to resistor tolerance. Monte-Carlo analysis was conducted to evaluate the error distribution for given resistor tolerance and opamp offset distribution and drift.

Table 11-1 shows the expected error (in that case unadjusted gain error) in case of using resistors with certain tolerance. Note that only R1 to R5 contributes to the accuracy of the current output path.

Table 11-1 Error Dependency on Resistor Tolerance
Resistor tolerance 1% 0.5% 0.1% Ideal Resistors
±3 sigma error 1.73% 0.87% 0.25% 0.18%
Max error 2.3% 1% 0.3% 0.25%
Output Current Histogram for 2.5V Input, and 0.5% Resistors Figure 11-1 Output Current Histogram for 2.5V Input, and 0.5% Resistors