GPON Class C++ SFP OLT Transceiver with Digital RSSI
1Features
1.1Single Fiber Transceiver with single mode SC receptacle 1490nm continuous-mode 2.488Gb/s DFB transmitter 1310nm burst-mode 1.244Gb/s APD receiver
1.2Complies with ITU-T G.984.2
1.3Digital Diagnostic Monitoring (DDM) with external calibrations
1.4LVPECL compatible data input /output
1.5LVTTL for Tx disable input and Tx_fault output
1.6LVTTL receiver Fast Burst Packet Detect indication
1.7Burst mode received signal strength indication (RSSI) function
1.8Complies with RoHS directive (2002/95/EC)
2Applications
Gigabit Passive Optical Network (GPON) OLT
3General
This is a high performance transceiver module for single fiber communications.It is designed to meet ITU G.984.2 requirements for optical line terminal (OLT) applications.
The 1490nm DFB LD transmitter has automatic power control (APC) function and temperature compensation circuitry to ensure stable optical power and extinction ratio over all operating temperature range. The transmitter meets Class 1 eye safety per IEC60825 and CDRH standards.
The receiver has a hermetically packaged APD-TIA (trans-impedance amplifier) pre-amplifier and a limiting amplifier with LVPECL compatible differential outputs. It features a Burst Packet Detect (SD) output which is LVTTL compatible. The SD output will come high after receiving the burst packet.
The module provides digital diagnostic information of its operating conditions and status, including transmitting power, laser bias current, module temperature, and supply voltage.
4Performance Specifications
4.1Absolute Maximum Ratings
Parameter
Symbol
Min.
Max.
Unit
Storage Temperature
Tst
-40
+85
°C
Operating relative humidity
RH
5
90
%
(Non- condensing)
Case Temperature (Operating)
TC
0
70
°C
Input Voltage
-
GND
Vcc
V
Power Supply Voltage
Vcc
0
3.6
V
4.2Recommended Operating Environment
Parameter
Symbol
Min.
Typ.
Max.
Unit
Power Supply Voltage
Vcc
+3.14
+3.3
+3.46
V
Power Supply Current
Icc
-
360
500
mA
Operating relative humidity
RH
5
85
%
(Non- condensing)
Case Temperature (Operating)
TC
0
-
70
°C
I2C clock frequency
-
100
400
KHz
Power consumption Max
-
-
-
1.65
W
4.3 1490nm Digital Transmitter E-O Characteristics
Note4.4.1: Measured with 1310nm, 1.244Gbps PRBS223-1, burst-mode optical input, ER=10dB, BER=1x10-10, Single burst packet length is 40us and packet interval is 40us.
4.5 Digital Diagnostic Monitoring Characteristics
Parameter
Symbol
Range
Accuracy
Transceiver Case
T
Measured transceiver case temperature over
±3°C
Temperature
specified operating range
Vcc
Internally measured transceiver supply
±3%
Supply Voltage
voltage ,3.0~3.6V
TX Bias Current
Id
Measured TX Bias current in uA
±10%
TX Output Power
Po
Measured TX Output Power in dBm Over the
±2dB
specified output power range
Received Optical Power
Pi
Measured RX Received Power in dBm Over the
±3dB
specified input power range, -10~-32dBm,
4.6 Timing Characteristics for Digital RSSI
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
ONU Optical Signal Length
Tont
350
-
-
ns
RSSI Trigger Delay
Ttri
0
50
-
ns
RSSI Trigger Signal Width
Tw
300
350
Tont- Ttri
ns
I2C read time
Tp
-
-
500
us
5EEPROM Section
6Pin Definitions
6.1Pin Diagram
6.2Pin Descriptions
Pin#
Logic
Name
Function
Notes
1
VeeT
Transmitter Ground
Note 7
2
LVTTL
TX_Fault
Transmitter Fault Indication
Note 1
3
LVTTL
TX_Disable
Transmitter Disable
Note 2
4
SDA
I
2
C Data
Note 3
5
SCL
I
2
C Clock
Note 3
6
MOD-DEF(0)
Internally grounded
7
LVTTL
Reset
Receiver Reset
Note 4
8
LVTTL
SD
Burst Packet Detect
Note 5
9
RSSI_Trigger
RSSI Trigger Signal from Host
Note 6
10
VeeR
Receiver Ground
Note7
11
VeeR
Receiver Ground
Note 7
12
RD-
Inv. Received Data Out
Note 8
13
RD+
Received Data Out
Note 8
14
VeeR
Receiver Ground
Note 7
15
VccR
Receiver Power
Note 9
16
VccT
Transmitter Power
Note 9
17
VeeT
Transmitter Ground
Note 7
18
TD+
Transmit Data In
Note 10
19
TD-
Inv. Transmit Data In
Note 10
20
VeeT
Transmitter Ground
Note 7
Notes:
1. TX Fault is an open collector output, which should be pulled up with a 4.7k~10kΩ resistor on the hostboard to a voltage between 2.0V and Vcc+0.3V. Logic 0 indicates normal operation; logic 1 indicates a laser fault of some kind. In the low state, the output will be pulled to less than 0.8V.
2. TX disable is an input that is used to shut down the transmitter optical output. It is pulled up within the module with a 4.7–10 KΩ resistor. It’s states are:
Low (0 – 0.8V):Transmitter on
(>0.8, < 2.0V):Undefined
High (2.0 – 3.465V):Transmitter Disabled
Open:Transmitter Disabled.
3. SDA and SCL is communication interface for I2C . They should be pulled up with a 4.7K – 10KΩ resistor on the host board. The pull-up voltage should be Vcc.
4. Reset is a LVTTL input which is used to clear receiver status before receiving the next burst packet.
5. BPD is a LVTTL output. High level indicates that burst packet is detected by the receiver.
6. RSSI_Trigger is a LVTTL input from host for starting ADC of digital RSSI circuit to sample the analog RSSI signal.
7. Vee is connected inside the SFP OLT transceiver.
8. RD- and RD+ are LVPECL differential outputs of the receiver, and externally DC-coupled to 100Ω differential lines at the user host board.
9. Vcc is the receiver and transmitter power supply, respectively. They are defined as 3.3V ±5% at the SFP connector pin. Maximum suppl in order to maintain the required voltage at the SFP input pin with 3.3V supply voltage. Vcc is internally connected inside the SFP OLT transceiver.
10. TD- and TD+ are the differential transmitter inputs. They are AC coupled differential lines with 100 Ω differential termination inside the module. The AC coupling is done inside the module and is thus not required on the host board.