Op-amp Finite Bandwidth Part 3/3: Compensation [Op-amp TS 16]

Op-amp tutorial series episode 16. In this video we explain the concept of op-amp compensation, discussing the internal compensation applied to modern op-amps, and using an example circuit with the AD8618 we explain how to compensate op-amps (externally) in-depth. The frequency compensation techniques we use with the AD8618 are reducing the divider resistances to compensate for a parasitic capacitance on the inverting input, using lead compensation in the form of a feed forward capacitor (or feed-forward capacitor) on the resistive divider, and using an isolation resistor to compensate the negative phase-shift introduced by the op-amp circuit's load capacitance. We also briefly touch on a few more compensation methods, including gain compensation, lag compensation, and in-the-loop compensation. Concepts discussed: op-amp internal compensation divider resistance changes compensation lead compensation with feed forward capacitor isolation resistor compensation for capacitive loads gain compensation lag compensation in-the-loop compensation for capacitive loads 00:00 Intro 00:54 Compensation Overview 01:45 Internal Compensation 05:44 Exernal Compensation 09:15 Comp. Example Starting Point 10:20 Divider Resistances Adjustment 12:27 Lead Compensation 16:49 Isolation Resistor 21:21 Results of Compensation 23:40 Advanced Comp. Methods 28:15 Outro