SBOA583 December   2023 OPA205 , OPA206 , OPA210 , OPA2206 , OPA2210 , OPA2392 , OPA2828 , OPA320 , OPA328 , OPA365 , OPA392 , OPA397 , OPA828

 

  1.   1
  2.   Abstract
  3. 1 Introduction
  4. 2 Circuit Configuration Impact on Common-Mode Range
  5. 3 Practical Input Limitations
  6. 4 Input Phase Reversal (Inversion)
  7. 5 Common-Mode Limitations Inside Bipolar Amplifiers
  8. 6 Common-Mode Limitations Inside CMOS Amplifiers
  9. 7 Rail-to-Rail CMOS Amplifiers
  10. 8 Output Swing Limitations Inside a Bipolar Op Amp
  11. 9 Linearity of Output Swing Specifications
  12. 10Output Voltage Swing vs Output Current
  13. 11Classic Bipolar vs Rail-to-Rail Output Stage for CMOS and Bipolar
  14. 12Rail-to-Rail Output and Open-Loop Gain Dependence
  15. 13Output Short-Circuit Protection
  16. 14Overload Recovery
  17. 15Supply Current During Input and Output Swing Limitations
  18. 16Summary
  19. 17References

10 Output Voltage Swing vs Output Current

We now know that data sheet tables provide an output swing saturation limit for a few different loads. Also, the open-loop gain specification from the data sheet specification table can be used to infer the linear output swing limitations. Beyond the specifications table, the data sheet provides a set of typical characteristic curves. The output voltage swing vs output current curve shows the typical output swing saturation limit for amplifiers (see Figure 10-1). The curve shows how output swing is impacted by a wide range of different load currents. The graph also shows how temperature impacts output swing. For CMOS, output swing gets worse for increasing temperature whereas for bipolar the output swing improves for increasing temperature due to the negative temperature coefficient of the base to emitter voltage (ΔVBE = –2 mV/°C). Finally, the output voltage swing curves illustrate the short-circuit current limit. The short-circuit limit is from an internal protection mechanism that limits the amplifier output stage drive when excessive current is drawn. On the graph, the short circuit current limit is the section where the output voltage drops rapidly at high current.

GUID-20230928-SS0I-HCXQ-ZCFG-BDKGVNQTFBKS-low.svg Figure 10-1 Output Voltage Swing vs Output Current for Classic Bipolar Output Stage OPA277