CY26121_08 Datasheet, PDF (1/7 Pages) Cypress Semiconductor – PacketClock™ Spread Spectrum Clock Generator

CY26121
PacketClock™ Spread Spectrum Clock
Generator
Features
■ Integrated phase-locked loop (PLL)
■ Low jitter, high-accuracy outputs
■ 3.3V operation
■ 25-MHz input frequency
■ 66.66-MHz or 33.33-MHz selectable output frequency (orig,
-3,-11,-31)
■ 33.33-MHz or 25-MHz selectable output frequency (-2,-21)
Benefits
■ High-performance PLL tailored for Spread Spectrum appli-
cation
■ Meets critical timing requirements in complex system designs
■ Enables application compatibility
■ Works with commonly available crystal or driven reference
■ Downspread Spread Spectrum with 30-kHz nominal
modulation frequency
Table 1. Frequency Table for CLKA-D
Part Number
CY26121
CY26121-2
CLKSEL=0
66.66 MHz
33.33 MHz
CY26121-3
CY26121-11
CY26121-21
CY26121-31
66.66 MHz
66.66 MHz
33.33 MHz
66.66 MHz
CLKSEL=1
33.33
25.00
33.33
33.33
25.00
33.33
Spread%
–2.8%
–2.8%
–1.4%
–2.8%
–2.8%
–1.4%
Parallel Crystal Load
6 pF
6 pF
6 pF
15 pF
15 pF
15 pF
Logic Block Diagram
25 MHz XIN
XOUT
SSON
OSC.
PLL
with
Modulation Control
Flash Configuration
CLKSEL
VDD AVDD AVSS VSS
OUTPUT
MULTIPLEXER
AND
DIVIDERS
VDDL
CLKA
CLKB
CLKC
CLKD
VSSL
REF
Cypress Semiconductor Corporation • 198 Champion Court
Document #: 38-07350 Rev. *A
• San Jose, CA 95134-1709 • 408-943-2600
Revised May 22, 2008
[+] Feedback