JAJU648A November 2018 – April 2022 TLV3601 , TLV3601-Q1 , TLV3603 , TLV3603-Q1
To get a pulse-response with fast rise and fall time, some overshoot and ringing on the rising and falling edges of the pulse is expected. The phase-margin of the OPA858 circuit is targeted at 55° to achieve a Q factor of 0.95. Use the circuit in Figure 2-10 to simulate the loop-gain of the OPA858. For more information on transimpedance amplifier stability theory and design, see the What You Need To Know About Transimpedance Amplifiers blog, part 1 and part 2.
The simulated loop-gain magnitude and phase plotted in Figure 2-11 predict a phase-margin of approximately 45°, which is lower than the expected calculated value because the calculation is only a first-order approximation.