Avoiding Performance Pitfalls for the Pulse Response of High-Speed Op Amps: Part 2 Second-Order Step Response Edge Rate Analysis by Michael Steffes
Part 1 of this 4 part series reviewed the first-order rise-time analysis found in academic and industry sources. It also reviewed the ideas of slew rate and full-power bandwidth and showed where some possible misconceptions might have arisen. Part 1 concluded with the idea that a very good understanding of a linear pulse response is the starting point for a step response analysis in applying a particular amplifier to an application. The discussion here will develop the peak slope and average rise times for a second-order low-pass step response. Again, some early simplifications in the literature have led to some long-term misconceptions on how to arrive at the correct dV/dt. This can lead to errors in comparing an output’s edge rate to the amplifier’s available slew rate. All of this discussion will be theoretical in nature where the results here will be compared to actual amplifiers in Part 3.
