Pulse Width Modulator Based on Second Generation Current Conveyor

Pulse Width Modulation (PWM) is a technique of changing ON and OFF time period of a waveform without changing its frequency or otherwise it is a series of pulses with different duty cycle time in the fixed period time, while duty time stands for the proportion of ´ON´ time in the period. In practice, it is determined and modified by a sequence of expected value or modulating signal. PWM signal can be generated by comparing a message signal (modulating signal) with the triangular carrier signal. In this paper, second generation current conveyor (CCII+) based PWM modulator is presented and concluded that CCII+ based pulse width modulation can yield the accurate PWM signal with better linearity, excellent temperature stability over wide operating carrier frequencies. First, the performance of the proposed circuit is examined using Cadence and the model parameters of a 0.18 μm CMOS process. Later, the circuit was built with commercially available Current Feedback Operational Amplifiers (AD 844 AN) and waveforms are presented; they demonstrate good agreement to the theoretical anticipation. PWM is employed in a wide variety of applications, ranging from measurement and communications to power control and conversion.