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

3.3 Slew Boost Summary

Most op amps do not have slew boost and slew rate. Whether an op amp has slew boost and slew rate requires assessing the listed data sheet value and the VID of the application. Boosted slew rate op amps have a more complex relationship between VID and SR. The data sheet does not always mention the presence of SR boost or the relationship with VID.

There are four methods to infer boost or no boost from a data sheet.

  1. Comparing the slew rate versus the gain bandwidth
  2. Comparing the quiescent current versus similar SR devices
  3. Evaluate the large signal response
  4. Evaluate the small signal response

Section 4 describes these four methods in depth, using the data sheets for the LMV831 and TLV9001 as examples.