Document
GS2985 Multi-Rate SDI Reclocker with Equalization & De-emphasis
Features
• SMPTE 424M, SMPTE 292M and SMPTE 259M-C compliant • Supports DVB-ASI at 270Mb/s • Single supply operation at 3.3V or 2.5V • 180mW typical power consumption (210mW with RCO
enabled) at 2.5V • Input signal equalization and output-signal de-emphasis
settings to compensate for board-trace dielectric losses • 4:1 input multiplexer patented technology • Choice of dual reclocked data outputs or one reclocked data
output and one clock output • Uses standard 27MHz crystal • Cascadable crystal buffer supports multiple reclockers using
a single crystal • Differential inputs and outputs
support DC coupling to industry-standard differential logic
on-chip 100Ω differential data input/output termination selectable 400mVppd or 800mVppd output swing on
each output seamless interface to other Gennum products • 4 wire SPI host interface for device configuration and monitoring • Standard logic control and status signal levels
• Auto and Manual modes for rate selection • Standards indication in Auto mode • Lock Detect Output • Mute, Bypass and Autobypass functions • SD/HD indication output to control GS2978 or GS2988 dual
slew-rate cable drivers • Operating temperature range: -40°C to +85°C • Small footprint QFN package (9mm x 9mm)
Package-compatible with GS2975A • Pb-free and RoHS compliant
Applications
• SMPTE 424M, SMPTE 292M and SMPTE 259M-C coaxial cable serial digital interfaces
Description
The GS2985 is a multi-rate serial digital reclocker designed to automatically recover the embedded clock from a digital video signal and retime the incoming video data. It will recover the embedded clock signal and retime the data from a SMPTE 424M, SMPTE 292M, or SMPTE 259M-C compliant digital video signal.
A serial host interface provides the ability to configure and monitor multiple GS2985 devices in a daisy-chain configuration.
Adjustable input trace equalization (EQ) for up to 40” of FR4 trace losses, and adjustable output de-emphasis (DE) for up to 20” of FR4 trace losses, can be configured via the host interface.
The GS2985 can operate in either auto or manual rate selection mode. In Auto mode, the device will automatically detect and lock onto incoming SMPTE SDI data signals at any supported rate. For single rate data systems, the GS2985 can be configured to operate in Manual mode. In both modes, the device requires only one external crystal to set the VCO frequency when not locked and provides adjustment free operation.
The GS2985 accepts industry-standard differential input levels including LVPECL and CML. The differential data and clock outputs feature selectable output swing via the host interface, ensuring compatibility with most industry-standard, terminated differential receivers.
The GS2985 features dual differential outputs. The second output can be configured to emit either the recovered clock signal or the re-timed video data. This output can also be disabled to save power.
In systems which require passing of non-SMPTE data rates, the GS2985 can be configured to either automatically or manually enter a bypass mode in order to pass the signal without reclocking.
The GS2985 is Pb-free, and the encapsulation compound does not contain halogenated flame retardant. This component and all homogeneous sub-components are RoHS compliant.
GS2985 Multi-Rate SDI Reclocker with Equalization &
De-emphasis
Data Sheet
36663 - 2
March 2010
www.gennum.com
1 of 44
XTALXTAL+
XTAL_BUF_OUT
XTAL OSC
Buffer
DDI0 DDI0
DDI1 DDI1
DDI2 DDI2
DDI3 DDI3
Equalizer/ Data Mux
Phase Frequency Detector
Phase Detector
Selectable Divide
LOS Detect
SPI
CP_CAP LF+ KBB
LDO
Retimer
Charge Pump
VCO
Selectable Divide
Control
Data Buffer
Clock/ Data Buffer
DDO0 DE0_EN DDO0
DDO1/RCO DE1_EN DDO1/RCO
1.8V
LDO
HIF SDI/EQ0_EN SDO/EQ1_EN SCK/EQ2_EN CS/EQ3_EN
DDI_SEL[1:0] LOS
Revision History
SS[1:0] AUTO/MAN
LOCKED
SD/HD
BYPASS
DATA/CLOCK DDO1_DISABLE
AUTOBYPASS
DATA_MUTE
GS2985 Functional Block Diagram
VDD_1p8
Version
2
ECR
153705
PCN
–
1
152592
–
0
152329
–
D
152240
–
C
152042
–
B
151967
–
A
151318
–
Date
March 2010
September 2009
July 2009 July 2009 June 2009 May 2009 April 2009
Changes and/or Modifications
Converted to Data Sheet. Updated Power numbers in Table 2-1: DC
Electrical Characteristics. Added Table 4-5: Suggested LOS Threshold Settings.
Updates to Section 4.15 Host Interface.
Converted document to Preliminary Data Sheet.
Added Figure 4-2: De-emphasis Waveform.
Removed ‘Proprietary & Confidential” from document.
Added Section 4.15 Host Interface.
New document.
GS2985 Multi-Rate SDI Reclocker with Equalization &
De-emphasis
Data Sheet
36663 - 2
March 2010
2 of 44
Contents
Features ................................................................................................................................................................. 1 Applications....................................................