16.1: Theory Overview

The triangle-square generator consists of two main parts: a comparator and a ramp generator or integrator. The circuit is self-sustaining by nature. The ramp generator requires a square wave input. It gets this signal from the comparator. The comparator in turn generates the square wave from the triangle wave appearing at the output of the ramp generator. The output frequency is determined primarily by the RC timing values of the ramp generator, and secondarily by the switching thresholds of the comparator. The practical output frequency limit is set by the bandwidth and slew rate of the op amps. At higher frequencies, slew rate limiting will noticeably slow the edges of the square wave. This will impact the output of the ramp generator and will affect both the linearity of the wave shapes and the output frequency.

---