SY89837U Datasheet, PDF (1/14 Pages) Micrel Semiconductor – PRECISION 1:8 LVPECL FANOUT BUFFER WITH 2:1 RUNT PULSE ELIMINATOR INPUT MUX

Micrel, Inc.
PRECISION 1:8 LVPECL FANOUT
BUFFER WITH 2:1 RUNT PULSE
ELIMINATOR INPUT MUX
Precision Edge^®
Precision E^Sd^Y8g⁹e^8®37U
SY89837U
FEATURES
„ Selects between two clocks, and provides 8
precision, low skew LVPECL output copies
„ Guaranteed AC performance over temperature and
supply voltage:
„ Wide operating frequency: 1kHz to >1.5GHz
• <975ps in-to-out t_pd
• <180ps t_r/t_f
• <40ps output-to-output skew
„ Unique input isolation design minimizes crosstalk
„ Ultra-low jitter design:
• <1ps_rms random jitter
• <1ps_rms cycle-to-cycle jitter
• <10ps_pp total jitter (clock)
• <0.7ps_rms MUX crosstalk induced jitter
„ Unique input termination and VT pin accepts DC- or
AC-coupled inputs (CML, PECL, LVDS)
„ 800mV LVPECL output swing
„ Power supply +2.5V ±5% or +3.3V ±10%
„ –40°C to +85°C industrial temperature range
„ Available in 32-pin (5mm x 5mm) MLF^® package
APPLICATIONS
„ Redundant clock distribution
„ Fail-safe clock protection
Precision Edge^®
DESCRIPTION
The SY89837U is a low jitter, low skew, high-speed 1:8
fanout buffer with a unique, 2:1 differential input multiplexer
(MUX) optimized for clock redundant switchover applications.
Unlike standard multiplexers, the SY89837U unique 2:1 runt
pulse eliminator (RPE) input MUX prevents any short cycles
or “runt” pulses during switchover. In addition, a unique fail-
safe input protection prevents metastable conditions when
the selected input clock fails to a static DC differential voltage
(differential input voltage drops below 200mV). The
SY89837U distributes clock frequencies from 1kHz to
1.5GHz, guaranteed, over temperature and voltage.
The differential input includes Micrel’s unique, 3-pin input
termination architecture that allows customers to interface
to any differential signal (AC- or DC-coupled) as small as
200mV without any level shifting or termination resistor
networks in the signal path. The outputs are 800mV, 100k
compatible LVPECL with fast rise/fall times guaranteed to
be less than 200ps.
The SY89837U operates from a +2.5V ±5% or
+3.3V ±10% supply and is guaranteed over the full industrial
temperature range of –40°C to +85°C. The SY89837U is
part of Micrel’s high-speed, Precision Edge^® product line.
All support documentation can be found on Micrel’s web
site at: www.micrel.com.
Precision Edge is a registered trademark of Micrel, Inc.
MicroLeadFrame and MLF are registered trademarks of Amkor Technology, Inc.
M9999-022007
[e-mail] or [phone]
1
Rev.: D Amendment: /0
Issue Date: February 2007