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PRELIMINARY
SY89801A
FEATURES
s
3.3V, 鈥?.9V power suppies
s
Differential LVPECL clock input
s
Differential HSTL/LVPECL outputs
s
Compatible with HP PA-8000 microprocessors
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Low-jitter source for all PA-8000 required timing
signals
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Available in 44-pin MQUAD package
DESCRIPTION
Micrel-Synergy's SY89801A PLL based clock generator
provides, in a single chip, all the necessary clocks for Hewlett-
Packard's PA-8000 Microprocessor.
Utilizing Micrel-Synergy's advanced PLL technology, the
SY89801A accepts a Positive-ECL (PECL) reference clock
input at 100MHz-132MHz, and provides precisely aligned,
ultra-low-jitter ratios of frequencies necessary for the operation
of the processor. In addition, the SY89801A provides the
"USYNC" synchronizing signals as required by the PA-8000.
The frequency ratios are 1:1, 4:3, 3:2, 5:3 and 2:1.
To facilitate direct interfacing to the PA-8000, the SY89801A
operates across +3.3 volt and -1.9 volt supplies. The processor
clock (PCLK), runway clock (RCLK) , and USYNC outputs are
HSTL-compatible. Additionally, there is a PECL-compatible
runway clock output (RCLKLV). The SY89801A requires only
a simple external series-RC loop filter.
Coupling Micrel-Synergy's advanced PLL technology with
our proprietary ASSET bipolar process has produced a
Timing Generator IC which meets the stringent requirements
of the PA-8000
碌P,
while setting a new standard for
performance and flexibility.
PIN CONFIGURATION
VEE
NC
NC
REF_CLK
REF_CLK
VCC
RCLKLV
RCLKLV
RCLK
RCLK
6
5
4
3
2
1 44 43 42 41 40
39
38
37
36
VEEA
NC
NC
FILP
FILN
VCCA
NC
NC
NC
NC
NC
VEE
7
8
9
10
11
12
13
14
15
16
17
18 19 20 21 22 23 24 25 26 27 28
VEE
PCLK1
PCLK1
PCLK2
PCLK2
VCC
USYNC
USYNC
NC
NC
VCC
TOP VIEW
MQUAD
M44-1
35
34
33
32
31
30
29
VCC
NC
NC
NC
FSEL0
FSEL1
FSEL2
VCC
RST
VEE
PIN NAMES
Pin
REF_CLK, REF_CLK
FILP, FILN
V
CCA
, V
EEA
RST
FSEL2-0
USYNC, USYNC
PCLK1-2, PCLK1-2
RCLK, RCLK
RCLKLV, RCLKLV
Function
Differential Input Ref. Clock
Filter Pins (Positive & Negative)
Analog V
CC
, V
EE
Master Reset
LVPECL Frequency Select Pins
Diff. HSTL Sync Signal for PA-8000
Diff. HSTL Processor Clock Signal
Diff. HSTL Runway Clock Signal
Diff. LVPECL Clock Signal
NC
Rev.: E
Amendment: /0
1
Issue Date: November 1998
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