SY54020R_09 Datasheet, PDF (1/14 Pages) Micrel Semiconductor – Low Voltage 1.2V/1.8V/2.5V CML 1:4 Fanout Buffer with /EN and Fail-Safe Input 3.2Gbps

SY54020R
Low Voltage 1.2V/1.8V/2.5V CML 1:4 Fanout
Buffer with /EN and Fail-Safe Input
3.2Gbps, 2.5GHz
General Description
The SY54020R is a fully differential, low voltage
1.2V/1.8V/2.5V CML 1:4 Fanout Buffer with active-low
Enable (/EN) and Fail-Safe Input (FSI). The Enable 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. When this device
is used as a clock fanout, disabling the downstream
clock may reduce system power. FSI is a special circuit
designed to sense the amplitude of the input signal and
to latch the output when an invalid or no signal is
present at the input. The SY54020R can process clock
signals up to 2.5 GHz or data patterns up to 3.2Gbps.
The differential input includes Micrel’s unique, 3-pin
input termination architecture that interfaces to LVPECL,
LVDS or CML differential signals as small as 100mV
(200mV_pp) without any level-shifting or termination
resistor networks in the signal path. For AC-coupled
input interface applications, an internal voltage
reference is provided to bias the V_T pin. The outputs are
CML, with extremely fast rise/fall times guaranteed to be
less than 100ps.
The SY54020R operates from a 2.5V ±5% core supply
and a 1.2V, 1.8V or 2.5V ±5% output supply and is
guaranteed over the full industrial temperature range
(–40°C to +85°C).
Datasheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Functional Block Diagram
Features
Precision Edge^®
• 1.2V/1.8V/2.5V CML 1:4 Fanout Buffer with FSI
• Active-low Enable (/EN) input to disable the outputs
• Guaranteed AC performance over temperature and
voltage:
– DC-to > 3.2Gbps Data throughput
– DC-to > 2.5GHz Clock throughput
– <400 ps propagation delay (IN-to-Q)
– <20ps within-device skew
– <100 ps rise/fall times
• Ultra-low jitter design
– <1ps_RMS cycle-to-cycle jitter
• High-speed CML outputs
• 2.5V ±5% V_CC , 1.2/1.8V/2.5V ±5% V_CCO power supply
operation
• Industrial temperature range: –40°C to +85°C
• Available in 16-pin (3mm x 3mm) MLF^® package
Applications
• SONET clock and data distribution
• Fibre Channel clock and data distribution
• Gigabit Ethernet clock and data distribution
Markets
• Storage
• ATE
• Test and measurement
• Enterprise networking equipment
• High-end servers
• Access
• Metro area network equipment
Precision Edge is a registered trademark of Micrel, Inc.
MLF and MicroLeadFrame are registered trademarks of Amkor Technology.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
April 2009
M9999-041409-A
[e-mail] or [phone]