3.3V 1:9 HIGH-PERFORMANCE,
LOW-VOLTAGE
BUS CLOCK DRIVER
ClockWorks™
SY89809L
FEATURES
DESCRIPTION
■ 3.3V core supply, 1.8V output supply for reduced
The SY89809L is a High-Performance Bus Clock Driver
with 9 differential HSTL (High-Speed Transceiver Logic)
output pairs. The part is designed for use in low-voltage
(3.3V/1.8V) applications which require a large number of
outputs to drive precisely aligned, ultralow skew signals to
their destination. The input is multiplexed from either HSTL
or LVPECL (Low-Voltage Positive-Emitter-Coupled Logic)
by the CLK_SEL pin. The Output Enable (OE) is
synchronous so that the outputs will only be enabled/
disabled when they are already in the LOW state. This
avoids any chance of generating a runt clock pulse when
the device is enabled/disabled as can happen with an
asynchronous control.
power
■ LVPECL and HSTL inputs
■ 9 differential HSTL (low-voltage swing) output pairs
■ HSTL outputs drive 50Ω to ground with no
offset voltage
■ 500MHz maximum clock frequency
■ Low part-to-part skew (200ps max.)
■ Low pin-to-pin skew (50ps max.)
■ Available in 32-pin TQFP package
The SY89809L features low pin-to-pin skew (50ps max.)
and low part-to-part skew (200ps max.)—performance
previously unachievable in a standard product having such
a high number of outputs. The SY89809L is available in a
single space saving package, enabling a lower overall cost
solution.
PIN CONFIGURATION
32 31 30 29 28 27 26 25
24
23
22
21
VCCO
Q3
VCCI
HSTL_CLK
HSTL_CLK
CLK_SEL
1
2
3
Q3
APPLICATIONS
Top View
TQFP
T32-1
Q4
4
5
6
7
8
20
19
18
17
Q4
■ High-performance PCs
■ Workstations
LVPECL_CLK
LVPECL_CLK
GND
Q5
Q5
■ Parallel processor-based systems
■ Other high-performance computing
■ Communications
OE
VCCO
9
10 11 12 13 14 15 16
PIN NAMES
LOGIC SYMBOL
Pin
Function
Differential HSTL Inputs
LVPECL_CLK, /LVPECL_CLK Differential LVPECL Inputs
CLK_SEL
HSTL_CLK, /HSTL_CLK
HSTL_CLK
0
HSTL_CLK
9
CLK_SEL
OE
Input CLK Select (LVTTL)
Output Enable (LVTTL)
Differential HSTL Outputs
Ground
Q0 – Q8
9
Q0 – Q8
LVPECL_CLK
1
Q0-Q8, /Q0-/Q8
GND
LEN
D
LVPECL_CLK
Q
VCCI
VCC Core
OE
VCCO
VCC Output
Rev.: A
Amendment: /0
Issue Date: March 2000
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