SY87739L_07 Datasheet, PDF (1/13 Pages) Micrel Semiconductor – PROTOCOL TRANSPARENT 3.3V 10MHz to 729MHz FRACTIONAL-N SYNTHESIZER

Micrel, Inc.
PROTOCOL TRANSPARENT
3.3V 10MHz to 729MHz
FRACTIONAL-N SYNTHESIZER
SY87739L
SY87739L
FEATURES
DESCRIPTION
„ Protocol transparent fractional-N synthesizer from
10MHz to 729MHz from a single 27MHz reference
oscillator
„ Generates exactly the correct frequency for common
transport protocols with or without FEC
„ Directly enables SY87721L CDR to lock onto any
data rate within its range
„ Exceeds BellCore and ITU jitter generation
specifications
„ Programmable via MicroWire™ interface
„ Available in 32-Pin EPAD-TQFP package
APPLICATIONS
„ Metro access system
„ Transponders
„ Multiplexers: access, Add Drop Mux
„ SONET/SDH/ATM-based transmission systems,
modules and test equipment
„ Broadband cross-connects
„ Fiber optic test equipment
„ Protocols supported:
OC-1, OC-3, OC-12, OC-48, ATM, Gigabit Ethernet,
Fast Ethernet, Fibre Channel, 2X Fibre Channel,
1394, InfiniBand, Proprietary Optical Transport
The SY87739L is a complete rate independent frequency
synthesizer integrated circuit. From a single reference
source, this device generates a differential PECL output
frequency from 10MHz up to 729MHz.
The SY87739L generates an exactly correct reference
frequency for common data transport protocols. This is
especially important in transponder applications, where a
standards compliant protocol data unit must be generated
downstream, even in the absence of any signal from the
associated upstream interface. In addition, the SY87739L
will generate exactly correct reference frequencies for
common data transport protocols augmented by forward
error correction codes. The SY87739L accepts configuration
via a MicroWire™ interface.
For proprietary applications, the SY87739L generates
reference frequencies guaranteed to enable the SY87721L
CDR to lock to any possible baud rate from 28Mbps to
2.7Gbps.
TYPICAL APPLICATIONS CIRCUIT
TYPICAL PERFORMANCE
0.1µF
0.1µF
2k
2k
31 30
26 25
V_CC
14
Saronix ⁸
SEL-2431C
27.0000MHz ₁
3 _REFCLK+
CLKOUT+ ²²
4
REFCLK-
SY87739L
CLKOUT-
21
7
121
121
121
121
V_CC
6 7 8 14
10, 25, 32
1, 9, 17, 18, 24
Cycle-to-Cycle Jitter
vs. Frequency
6
5
4
3
2
1
0
0 100 200 300 400 500 600 700 800
OUTPUT FREQUENCY (MHz)
Microcontroller
AnyClock and AnyRate are registered trademarks of Micrel, Inc.
MicroWire is a trademark of National Semiconductor.
M9999-062807
[e-mail] or [phone]
1
Rev.: E Amendment: /0
Issue Date: June 2007