Chris Wilson
Member
Attached is the schematic of a frequency doubler. It takes a 136kHz input and doubles it to give a 472kHz output. I am not sure how the IC and the two transistors function. The IC is a 74HCT4046 and its data sheet is available here: https://www.farnell.com/datasheets/66679.pdf?_ga=1.131595913.701848857.1475733716
Finally, as a beginner I am unsure about the note on the schematic regarding a 51 Ohm resistor, I assume it's for impedance matching, but what I don't understand is why it would be a series resistor at the doubler's output, but a parallel one on the Class D amp input. Thanks
Finally, as a beginner I am unsure about the note on the schematic regarding a 51 Ohm resistor, I assume it's for impedance matching, but what I don't understand is why it would be a series resistor at the doubler's output, but a parallel one on the Class D amp input. Thanks