Triangle Wave Generator Circuit using Op-amp

The Triangle Wave Generator Circuit uses an LM358 operational amplifier along with resistors, ceramic and electrolytic capacitors configured on a breadboard to produce a continuous triangular waveform. At its core, the circuit relies on a feedback loop combining an integrator and a comparator stage. The op-amp configuration continuously charges and discharges the capacitors through the resistor network, alternating the output voltage between positive and negative saturation limits. As the 1nF ceramic capacitor and 1uF electrolytic capacitor charge and discharge, the voltage across them ramps up and down linearly rather than switching instantly. This linear charging action creates the sloping sides of the triangle wave. The 1K, 10K, and 100K resistors set the precise voltage thresholds and time constants that dictate the frequency and amplitude of the output signal. By using the oscilloscope, you can visually observe how the switching thresholds trigger the reversal of the capacitor charging direction, resulting in a clean, repeating triangle wave output without needing any microcontroller or software programming.

Used in function generators, transistor curve tracers, PWM controllers, class D amplifiers, and audio tone generators.