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Pin-compatible with Cypress CY7B9910
Available in SOIC package
DESCRIPTION:
The IDT59910A is a high fanout phase lock loop clock driver in-
tended for high performance computing and data-communications appli-
cations. The IDT59910A has eight zero delay TTL outputs.
The IDT59910A maintains Cypress CY7B9910 compatibility while pro-
viding two additional features: Synchronous Output Enable (GND/sOE),
and Positive/Negative Edge Synchronization (V
CCQ
/PE). When the GND/
sOE
pin is held low, all the outputs are synchronously enabled (CY7B9910
compatibility). However, if GND/sOE is held high, all the outputs except
Q2 and Q3 are synchronously disabled.
Furthermore, when the V
CCQ
/PE is held high, all the outputs are syn-
chronized with the positive edge of the REF clock input (CY7B9910
compatibility). When V
CCQ
/PE is held low, all the outputs are synchro-
nized with the negative edge of REF.
The FB signal is compared with the input REF signal at the phase
detector in order to drive the VCO. Phase differences cause the VCO of
the PLL to adjust upwards or downwards accordingly.
An internal loop filter moderates the response of the VCO to the
phase detector. The loop filter transfer function has been chosen to
provide minimal jitter (or frequency variation) while still providing accu-
rate responses to input frequency changes.
FUNCTIONAL BLOCK DIAGRAM
V
CCQ
/PE
GND/sOE
Q
0
Q
1
Q
2
Q
3
PLL
REF
Q
4
Q
5
FS
Q
6
Q
7
FB
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGES
1
c
2001
Integrated Device Technology, Inc.
SEPTEMBER 2001
DSC 5845/1