PE97632 Datasheet, PDF (9/15 Pages) List of Unclassifed Manufacturers – 3.2 GHz Delta-Sigma modulated Fractional-N Frequency Synthesizer for Low Phase Noise Applications

Functional Description
The PE97632 consists of a prescaler, counters,
an 18-bit delta-sigma modulator (DSM) and a
phase detector. The dual modulus prescaler
divides the VCO frequency by either 10 or 11,
depending on the value of the modulus select.
Counters “R” and “M” divide the reference and
prescaler output, respectively, by integer values
stored in a 20-bit register. An additional counter
(“A”) is used in the modulus select logic. The DSM
Figure 9. Functional Block Diagram
PE97632
Product Specification
modulates the “A” counter outputs in order to
achieve the desired fractional step.
The phase-frequency detector generates up and
down frequency control signals. Data is written
into the internal registers via the three wire serial
bus. There are also various operational and test
modes and a lock detect output.
f_r
R Counter
(6-bit)
f_c
R(5:0)
Sdata
Control
Pins
Control
Logic
M(8:0)
K(17:0)
A(3:0)
Phase
Detector
PD_U
PD_D
Modulus
Select
DSM
+
Logic
LD
Cext
2 k
F_in
F_in
10/11
Prescaler
M Counter
(9-bit)
f_p
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Document No. 70-0205-07 │ UltraCMOS™ RFIC Solutions