A wide range PWM signal frequency converter with the identical duty cycle

A wide frequency range PWM signal frequency converter is presented in this paper. Compared to the traditional frequency converter, an improved approach is designed to decrease the duty cycle error between the input signal and the output signal. By capacitor charge storage method, the duty cycle sampling error at the rising/falling edge of the input PWM signal is reduced significantly. The novel frequency transition method is designed and implemented in a 0.5μm standard CMOS process for a low voltage DC fan motor driver. The simulations and experimental results show that the improved frequency conversion approach is available in many applications.