PROGRAMMABLE
FREQUENCY SYNTHESIZER
(25MHz to 400MHz)
FEATURES
s
Improved jitter performance over SY89429
s
25MHz to 400MHz differential PECL outputs
s
±
25ps peak-to-peak output jitter
s
Minimal frequency over-shoot
s
Synthesized architecture
s
Serial 3 wire interface
s
Parallel interface for power-on
s
Internal quartz reference oscillator driven by quartz
crystal or PECL source
s
PECL output can operate with either +3.3V or +5V
VCC_OUT power supply
s
External loop filter optimizes performance/cost
s
Applications note (AN-06) for ease of design-ins
s
Available in PLCC and SOIC 28-pin packages
ClockWorks™
SY89429A
DESCRIPTION
The SY89429A is a general purpose, synthesized clock
source targeting applications that require both serial and
parallel interfaces. Its internal VCO will operate over a
range of frequencies from 400MHz to 800MHz. The
differential PECL output can be configured to be the VCO
frequency divided by 2, 4, 8 or 16. With the output configured
to divide the VCO frequency by 2, and with a 16MHz
external quartz crystal used to provide the reference
frequency, the output frequency can be specified in 1MHz
steps.
PIN CONFIGURATION
GND (TTL)
V
CC
(TTL)
V
CC_OUT
FOUT
FOUT
GND
TEST
M[0]
M[1]
M[2]
18
17
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
P
_LOAD
V
CC1
XTAL
2
XTAL
1
LOOP
_REF
LOOP
_FILTER
V
CC_QUIET
S
_LOAD
S
_DATA
S
_CLOCK
V
CC_OUT
FOUT
FOUT
GND
25 24 23 22 21 20 19
S
_CLOCK
S
_DATA
S
_LOAD
V
CC_QUIET
LOOP
_FILTER
LOOP_
REF
XTAL1
26
27
28
1
2
3
4
5
6
7
8
9
10 11
N[1]
N[0]
M[8]
M[7]
M[6]
M[5]
M[4]
M[3]
M[4]
M[5]
M[6]
M[7]
M[8]
PLCC
TOP VIEW
16
15
14
13
12
TOP VIEW
SOIC
Z28-1
22
21
20
19
18
17
16
15
P
_LOAD
M[0]
M[1]
M[2]
XTAL2
V
CC1
M[3]
N[0]
N[1]
GND (TTL)
APPLICATIONS
s
s
s
s
s
s
s
s
Workstations
Advanced communications
High end consumer
High-performance computing
RISC CPU clock
Graphics pixel clock
Test equipment
Other high-performance processor-based
applications
1
TEST
V
CC
(TTL)
Rev.: H
Amendment: /0
Issue Date: October, 1998
MICREL [ MICREL SEMICONDUCTOR ]
