GO2925 1310nm Optical Transceiver
Features
• Best-in-class optical receiver sensitivity: -22dBm
(over all supported video rates with pathological data)
• Robust error free transmission of signals from 50Mbps
to 3Gbps with up to 30km single-mode fiber
• Maximum distance of 10km under worst-case
conditions and 3Gbps video pathological signals
• Supports video pathological patterns for SD-SDI,
HD-SDI and 3G-SDI
• Hot-pluggable
• Laser disable pin
• Diagnose and control via I2C interface including:
Monitoring of the laser bias current, average output
power, receive optical power, supply voltage and
temperature
Alarm reporting
Module ID polling
• Single +3.3V power supply
• Low Power Consumption— typical 650mW
• RoHS compliant
• Operating case temperature range: 0°C to 70°C
• 56.5mm x 13.4mm x 8.6mm SFP Package
• SMPTE 297-2006 compatible
Applications
• SMPTE 297-2006 compatible optical-to-electrical
interfaces
• Broadcast cameras
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Description
The GO2925 is an optical transceiver module engineered
for exceptional performance in the presence of SDI
pathological patterns. The transceiver features
best-in-class optical receiver sensitivity for SMPTE 259M,
SMPTE 344M, SMPTE 292M and SMPTE 424M serial rates,
thus providing superior optical link budget and robustness.
The GO2925 contains a PIN photodiode receiver and a
1310nm Fabry-Perot laser transmitter designed to provide
error-free transmission of signals from 50Mbps to 3Gbps
over single mode fiber (9/125). It is also hot-pluggable.
The GO2925 provides extensive operational status
monitoring through an I2C interface. Input optical power is
monitored in the receiver; output optical power and bias
current are monitored in the transmitter. Other operating
conditions, such as power supply and operating
temperature, are also monitored. If a monitored parameter
falls outside the pre-defined range, an alarm flag associated
with the parameter will be raised.
Ordering Information
Part Number
GO2925-31CM
Package
SFP
Temperature Range
TCASE= 0°C to 70°C
GO2925 3G-SDI 1310nm Video Optical Transceiver Module
GO2925 1310nm Optical Transceiver
Data Sheet
52728 - 1
November 2009
www.gennum.com
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2.2 Pin Descriptions
Table 2-1: Pin Descriptions
Number
Name
Type
Description
1
VEE_TX
Ground
Transmitter Ground connection
2
TX_FAULT
Output
Transmitter fault indicator (Active high,
open-drain)
3 NC No Connect No Connection
4
VEE_TX
Ground
Transmitter Ground connection
5
I2C CLK
Digital (Input) I2C Clock
6
I2C DATA
Digital
I2C Data
(Bi-Directional)
7
VEE_RX
Ground
Receiver Ground connection
8
RX_LOS
Output
Receiver loss of signal indicator (Active
high, open-drain)
9 NC No Connect No Connection
10 NC No Connect No Connection
11
VEE_RX
Ground
Receiver Ground connection
12
RD-
Output
Negative differential output (AC-coupled
internally)
13
RD+
Output
Positive differential output (AC-coupled
internally)
14
VEE_RX
Ground
Receiver Ground connection
15
VCC_RX
Power
Receiver power supply
16
VCC_TX
Power
Transmitter power supply
17
VEE_TX
Ground
Transmitter Ground connection
18
TD+
Input
Positive differential input (AC-coupled
internally)
19
TD-
Input
Negative differential input (AC-coupled
internally)
20
TX_DIS
Digital (Input) Transmitter Disable. Laser is disabled when
high. Internal 6kΩ pull-up.
NOTES:
1. All VEE_TX are connected together inside the module
2. All VEE_RX are connected together inside the module
GO2925 1310nm Optical Transceiver
Data Sheet
52728 - 1
November 2009
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6 Page
4. Digital Diagnostics
4.1 I2C Bus Interface
The I2C interface allows reading of diagnostic information from the module. It is
comprised of I2C DATA and I2C CLK pins. All address and data bytes are transmitted
through the I2C DATA pin. The I2C DATA and I2C CLK pins are open-collector and they
must be pulled high (4.75kΩ recommended) externally to the module. Data on the I2C
DATA pin may only change during I2C CLK 'low' time periods. Data changes during I2C
CLK 'high' periods will indicate either a START or STOP condition. Operations and
conditions are described as follows:
START Condition
The START condition is originated by the host. A high-to-low transition of I2C DATA
while I2C CLK 'high' defines a START condition that must precede any other command,
see Figure 4-1.
STOP Condition
The STOP condition is originated by the host. A low-to-high transition of I2C DATA while
I2C CLK 'high' defines a STOP condition, see Figure 4-1.
START
STOP
I2C DATA
I2C CLK
Figure 4-1: I2C START and STOP Condition
Acknowledge or ACK Condition
The acknowledge condition occurs when the I2C DATA pin is pulled 'low' during the
ninth clock pulse following an address or data byte. The module originates this
condition after it has received a block or data address. The host originates this condition
during a sequential address read operation.
Addressing Operation
The module must receive a block address following a START condition to enable a read
operation. The block address is clocked into the module MSB to LSB. There are three read
operations: current address read, random read, and sequential address read.
Note that by the convention specified in the SFP MSA, 7-bit block addresses are left
shifted by one bit when expressing them in hex. Block addresses for the different
GO2925 1310nm Optical Transceiver
Data Sheet
52728 - 1
November 2009
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12 Page
