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PLL

I was wondering if anyone knows how the N divider worked on the
Motorola PLL Frequency Synth MC145151-2. It has pins N0-N13. I am
trying to input a 2kHz wave into the divider and compare it to a 1kHz
ref freqeuncy. I would divide by two so I figured I would set N1 high
and set the rest low. This does not seem to work. Any suggestions?
 
P

PeteS

Jan 1, 1970
0
The datasheet is perfectly clear on the part.

The device you have is designed for single modulus prescalers

The output is given by (with no addition to the prescaler, T/R pin = 1)

Fosc / (RefDiv) * prescalerDiv assuming you are driving Fin from a VCO
(see the datasheet)

Where RefDiv is specified on page 3 of the datasheet (RA2 - RA0) and
prescalerDiv is a binary number with N0 as the least significant bit.

Datasheet here

http://www.freescale.com/files/rf_if/doc/data_sheet/MC145151-2.pdf

Cheers

PeteS
 
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