AN2266 - PSoC® 1 - 16-Bit PWM/PWM-DACs using One Digital PSoC® Block

Sometimes an 8-bit PWM does not provide you with enough resolution. The PWM16 User Module is an option, but it takes an extra digital block, and produces a PWM waveform of a much lower frequency. AN2266 describes an alternative that uses only one digital block, and includes some practical ways to use it to implement a high-resolution DAC.

Introduction

A pulse-width modulator (PWM) is basically a circuit that repeatedly measures out a fixed period of time, and outputs a signal that is active for some percentage of that time (termed the duty cycle). That signal is generally used to provide power to some form of load, thereby providing it with a variable amount of power. By its nature, the PWM provides power in discrete pulses, so to be useful, the load itself must be capable of storing, or integrating much of that power, from one pulse to the next.