Analog Circuit Design Volume 2

Chapter 17

High speed comparator techniques

Jim Williams

Introduction

Comparators may be the most underrated and underutilized monolithic linear component. This is unfortunate because comparators are one of the most flexible and universally applicable components available. In large measure the lack of recognition is due to the IC op amp, whose versatility allows it to dominate the analog design world. Comparators are frequently perceived as devices, which crudely express analog signals in digital form—a 1-bit A/D converter. Strictly speaking, this viewpoint is correct. It is also wastefully constrictive in its outlook. Comparators don’t “just compare” in the same way that op amps don’t “just amplify”.

Comparators, in particular high speed comparators, ...