SLOA332 july   2023 LMV821-N , LMV831 , OPA2991 , OPA345 , OPA376 , OPA376-Q1 , OPA377 , OPA377-Q1 , OPA4991 , OPA991 , TL074 , TLV376 , TLV9001 , TLV9002 , TS321

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Slew Rate Definition
    1. 1.1 Virtual Ground and Slew Rate
  5. 2Bipolar Op Amp Slew Rate Example
  6. 3CMOS Op Amp Slew Rate Example
    1. 3.1 Slew Boost Example 1
    2. 3.2 Slew Boost Example 2
    3. 3.3 Slew Boost Summary
  7. 4Four Methods to Determine Boost or No Boost Using the Data Sheet
  8. 5Slew Rate Dependencies on Circuit Signal Levels and Op Amp Gain Set by Feedback Network
  9. 6How Much Output Slew Rate is Needed to Support a Sine Wave or Other Non-step Inputs
  10. 7Stability Also Plays a Role in Observed Slew Rate
  11. 8Summary
  12. 9References

7 Stability Also Plays a Role in Observed Slew Rate

Very stable circuits with 90 degrees or more phase margins have longer rise times with slower observed SR because feedback is fully negative. The advantage of very stable circuits is the lack of overshoot. Critically stable and poor stability circuits with 45 degrees or less phase margin have a significant positive feedback effect that shortens edge times and increases observed SR at the expense of having overshoot, ringing, or possible oscillation.