LUCW3000CCN AGERE [Agere Systems], LUCW3000CCN Datasheet - Page 8

• Manufacturer Part Number: LUCW3000CCN
• Description: W3000 PLL Dual-Band Frequency Synthesizer
• Manufacturer: AGERE [Agere Systems]

W3000 PLL Dual-Band Frequency Synthesizer
PLL Programming Information
The oscillator frequency is selected according to the following expression:
where:
P/(P + 1) = Dual modulus prescaler
Example
You wish to have a VCO operating at 1172 MHz, ability to step the frequency in 200 kHz steps, and a reference
clock at 13 MHz.
Step 1:
Calculate the reference counter ratio R
Step 2: Calculate M & A
M is an integer, and so is A; therefore, M = 91, and A = 36.
8
M
R
f
A
f
VCO
REF
R
1172
(
f
5860
VCO
64
64
= VCO frequency
= Programmable counter ratio (2 to 2047), M > A
= Swallow counter ratio (0 to M – 1 or 127)
= External reference oscillator frequency
= Reference counter ratio (2 to 2047)
f
VCO
*
200
13
M
P (
91
MHz
(
64
) A
kHz
P (
*
36
64
M
*
*
M
M
)
1172
65
)
R
)
65
A
R
13
A
A
f *
*
*
65
f *
REF
13
REF
5860
Advance Data Sheet
Lucent Technologies Inc.
December 1999