Frequency Doubler Digital Circuit. Digital frequency doubler circuit application contained in the system electronics such as audio producing organ or keyboard. The reference frequency in this circuit drives the input of an exclusive or gate xor gate u2 as well as the input to a delay circuit.
Consisting of r1 c1 and comparator u1 the delay circuit drives the xor gate s second input. Note too that you might need to change which pin on the 595 you feed back to the pll. Mike n1jez located an article 1 by k6iql describing a frequency multiplier for this application.
This circuit uses one cmos quad two input nand gate package type 4011.
The function of the digital frequency doubler for multiplying two input frequencies. For proof of concept it worked well. The reference frequency in this circuit drives the input of an exclusive or gate xor gate u2 as well as the input to a delay circuit. The signal is applied to the input of n1.
