Frequency multiplier which allow adjust the duty cycle ..#2

Thread Starter


Joined Feb 17, 2023
I am new here and I want to tell you that it's possible to design a frequency multiplier circuit topology where the input and output can have the same duty cycle. One such topology is the charge pump frequency doubler.

In a charge pump frequency doubler, the input signal is first fed into a flip-flop to divide the input frequency by two. The divided output is then used to drive a charge pump, which generates a doubled voltage that is used to switch the output of another flip-flop. The output of the second flip-flop is then a signal with twice the frequency of the input signal, and the duty cycle of the output signal can be made to match the duty cycle of the input signal by properly setting the flip-flop and charge pump parameters.

To ensure that the output has the same duty cycle as the input, the two flip-flops should be edge-triggered D flip-flops with the same setup and hold times. The charge pump should be designed to generate a voltage that is just sufficient to switch the second flip-flop output, so that the output has the same duty cycle as the input. The parameters of the charge pump can be adjusted to fine-tune the output duty cycle to match the input duty cycle.

It's worth noting that charge pump frequency doublers are generally less efficient than other types of frequency multipliers, and may produce more jitter in the output signal. However, they can be useful in applications where maintaining the input duty cycle is critical.

I hope this information helps you with your project!