CY23S02
Document #: 38-07155 Rev. *C
Page Page 2 of 7 of 7
Overview
The CY23S02 is a two-output zero delay buffer and frequency
multiplier. It provides an external feedback path allowing
maximum flexibility when implementing the Zero Delay
feature. This is explained further in the sections of this data
sheet titled “How to Implement Zero Delay,” and “Inserting
Other Devices in Feedback Path.”
The CY23S02 is a pin-compatible upgrade of the Cypress
W42C70-01. The CY23S02 addresses some application
dependent problems experienced by users of the older device.
Most importantly, it addresses the tracking skew problem
induced by a reference that has Spread Spectrum Timing
enabled on it.
Spread Aware
Many systems being designed now utilize a technology called
Spread Spectrum Frequency Timing Generation. Cypress has
been one of the pioneers of SSFTG development, and we
designed this product so as not to filter off the Spread
Spectrum feature of the Reference input, assuming it exists.
When a zero delay buffer is not designed to pass the SS
feature through, the result is a significant amount of tracking
skew which may cause problems in systems requiring
synchronization.
For more details on Spread Spectrum timing technology,
please see the Cypress application note titled, “EMI
Suppression Techniques with Spread Spectrum Frequency
Timing Generator (SSFTG) ICs.”
Pin Definitions
Pin Name
Pin No.
Pin
Type
Pin Description
IN
2
I
Reference Input: The output signals will be synchronized to this signal.
FBIN
1
I
Feedback Input: This input must be fed by one of the outputs (OUT1 or OUT2) to
ensure proper functionality. If the trace between FBIN and the output pin being used
for feedback is equal in length to the traces between the outputs and the signal desti-
nations, then the signals received at the destinations will be synchronized to the REF
signal input (IN).
OUT1
6
O
Output 1: The frequency of the signal provided by this pin is determined by the
feedback signal connected to FBIN, and the FS0:1 inputs (see Table 1).
OUT2
8
O
Output 2: The frequency of the signal provided by this pin is one-half of the frequency
of OUT1. See Table 1.
VDD
7
P
Power Connections: Connect to 3.3V or 5V. This pin should be bypassed with a
0.1-
µF decoupling capacitor. Use ferrite beads to help reduce noise for optimal jitter
performance.
GND
3
P
Ground Connection: Connect all grounds to the common system ground plane.
FS0:1
4, 5
I
Function Select Inputs: Tie to VDD (HIGH, 1) or GND (LOW, 0) as desired per
Table 1.