510MHz divider with 100/1000

2500MHz divider with 1000

• LMX2330 is Dual Frequency Synthesizer for RF

• It has an interesting option for amateurs:   Output signals of Counters may be accessed from outside.

• LMX2330 contains  2  Phase Locked Loops: IF and RF.
  IF PLL – max. 510MHz
  RF PLL – max. 2500MHz

• Power Input: -10…+4dBm.
  Sensitivity is better (-15dBm) for 3V power supply.

• Divided signal is available at pin FoLD (10).
  Both prescalers can’t be accessed simultaneously!

For testing and registry calculation, I used Code Loader 4 from National Semiconductor.

Calculated values of the registers must be inserted into the source program written for PIC16F628A. Then the source code is compiled with MPLAB.

For high values of counter, the output signal is very narrow. RF Counter can theoretically divide between 96...65631 (P=32).

Not all values gave good results.
Example: N = 200 (P= 32) , Freq. = 400 MHz; Frequency counter display 2,020202MHz. I don't know what is the problem, possible shape of the output signal...

Schematic Diagram
PCB + Layout File
Source Code PIC16F628

HEX File for PIC16F628:
IF Prescaler - ratio = 100
IF Prescaler - ratio = 1000
RF Prescaler - ratio = 1000

How to calculate value of registers with Code Loader 4
For more info please read: LMX2324 Tutorial MPLAB

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