Frequency Multiplication and Filters

Discussion in 'The Projects Forum' started by folutade, Jul 23, 2010.

  1. folutade

    Thread Starter New Member

    Jul 22, 2010
    I'm trying to use a switched cap filter with a cutoff frequency of 60 kHz. The filter needs 20:1 clk to fc ratio so I need a 1.2MHz clock. I have a 120 kHz signal on the board that I wanted to use as the clock and was wondering if there is any good way to multiply the signal's frequency. I was looking at PLL's for multiplication but most off the shelf solutions had minimum input frequencies around 5 MHz.
  2. Bernard

    AAC Fanatic!

    Aug 7, 2008
    At 15V , 4046 PPL typ operating freq. 1.6 MHz., so divide Vco of 1.2 MHz by 10 for 120 kHz input to comparator in.