Abstract

This paper proposes a modified PWM circuit using OTRA based analog timer circuit. Designing a pulse width modulator circuit by employing the proposed analog timer circuit results in a waveform having variable duty cycle and time period. The timer circuit consists of comparators designed using OTRA and flip flops. The fabrication of timer circuit on a monolithic integrated circuit is easier as the carrier signal type is exponential and no additional circuitry is needed unlike for triangular and sawtooth pulses. The process parameters of 0.5 µm CMOS have been used for performing an intensive simulation of the proposed PWM circuit.