ADF411X PLL N counter, R counter range

Prescaler choices: 8/9, 16/17, 32/33, 64/65

RF/P <= 200 MHz


The N counter is acutally a dual modulus prescaler that is controlled by the A and B counters. Both A and B counters are toggled each time by the prescaler's output pulses. In operation, the RF signal is divided by P+1 A times and by P (B-A) times. Thus the net division is N=A*(P+1)+(B-A)*P

N= BP + A

A, B Ranges
B = 3 to 8191
A = 0 to 63

R counter range 1 to 16383