Product Features：
l Up to 26.5625Gbps data rate per channel by PAM4 modulation；
l 4 duplex channels transmitters and receivers；
l 4x26.5625 GBd PAM4 EML lasers；
l Single +3.3V power supply；
l SFF-8636 management interface；
l Hot-pluggable QSFP56 form factor；
l LC connector；
l Low power dissipation:<6.5W；
l QSFP+ 28Gb/s compliant；
l Operating temperature range: 0℃ ~ +70 ℃；
l Compliant with ROHS；
I. Pin Diagram
Electrical Pin-out Details
II. Pin Descriptions
Pin | Symbol | Name/Description | |
1 | GND | Ground | 1 |
2 | Tx2n | Transmitter Inverted Data Input | |
3 | Tx2p | Transmitter Non-Inverted Data Input | |
4 | GND | Ground | 1 |
5 | Tx4n | Transmitter Inverted Data Input | |
6 | Tx4p | Transmitter Non-Inverted Data Input | |
7 | GND | Ground | 1 |
8 | ModSe1L | Module Select | |
9 | ResetL | Module Reset | |
10 | Vcc Rx | +3.3V Power supply receiver | |
11 | SCL | 2-wire serial interface clock | |
12 | SDA | 2-wire serial interface data | |
13 | GND | Ground | 1 |
14 | Rx3p | Receiver Non-Inverted Data Output | |
15 | Rx3n | Receiver Inverted Data Output | |
16 | GND | Ground | 1 |
17 | Rx1p | Receiver Non-Inverted Data Output | |
18 | Rx1n | Receiver Inverted Data Output | |
19 | GND | Ground | 1 |
20 | GND | Ground | 1 |
21 | Rx2n | Receiver Inverted Data Output | |
22 | Rx2p | Receiver Non-Inverted Data Output | |
23 | GND | Ground | 1 |
24 | Rx4n | Receiver Inverted Data Output | |
25 | Rx4p | Receiver Non-Inverted Data Output | |
26 | GND | Ground | 1 |
27 | ModPrSL | Module Present | |
28 | IntL | Interrupt | |
29 | Vcc Tx | +3.3V Power supply transmitter | |
30 | Vcc1 | +3.3V Power Supply | |
31 | LPMode | Low Power Mode | |
32 | GND | Ground | 1 |
33 | Tx3p | Transmitter Non-Inverted Data Input | |
34 | Tx3n | Transmitter Inverted Data Input | |
35 | GND | Ground | 1 |
36 | Tx1p | Transmitter Non-Inverted Data Input | |
37 | Tx1n | Transmitter Inverted Data Input | |
38 | GND | Ground | 1 |
Note：QSFP56 uses common ground (GND) for all signals and supply (power). All the common within the QSFP56 module and all module voltages are referenced to this potential unless otherwise noted. Connected theses directly to the host board signal common ground plane.
VccRx, VccRx1, Vcc1, Vcc2, VccTx, and VccTx1 shall be applied concurrently. Requirements defined for the host side of the Host Card Edge Connector are listed in Table 4. VccRx, VccRx1, Vcc1, Vcc2, VccTx, and VccTx1 may be internally connected within the module in any combination. The connector Vcc pins are each rated for a maximum current of 1000mA.
All Vendor Specific, Reserved and No Connect pins may be terminated with 50 ohms to ground on the host. Pad 65 (No Connect) shall be left unconnected within the module. Vendor Specific and Reserved pads shall have an impedance to GND that is greater than 10 kOhms and less than 100pF
III. Absolute Maximum Ratings
Parameter | Symbol | Min. | Typ. | Max. | Unit | Ref. |
Storage Temperature | TS | -40 | 85 | ºC | ||
Storage Ambient Humidity | HA | 0 | 85 | % | ||
Maximum Supply Voltage | VCC | -0.5 | 3.6 | V |
IV. Recommended Operating Conditions
Data Rate Spcifications | Symbol | Min. | Typ. | Max. | Unit | Ref. |
Supply Voltage | Vcc | 3.13 | 3.3 | 3.47 | V | |
Baud Rate(per channel ) PAM4 | BR | 26.5625 | GBd | |||
Operating Case Temperature | Tc | 0 | 70 | ℃ |
V. Optical Interface Characteristics
Parameter Unit | Symbol | Min. | Min. | Typ. | Max. | Ref. |
Transmitter(per lane) | ||||||
Signaling Speed per Lane | GBd | 26.5625 | ||||
Modulation format | PAM4 | |||||
Center wavelength | nm | 1264.5 | 1337.5 | CWDM | ||
Side-mode suppression Ratio | SMSR | dB | 30 | |||
Average Launch Power per Lane | TXPx | dBm | -4.2 | 4.7 | ||
Tx OMA per lane | TxOMA | dBm | -1.2 | 4.5 | ||
Launch power in OMA outer minus TDECQ(min) | TDECQ | -2.6 | 4.5 | dB | ER≥4.5dB | |
-2.5 | ER＜4.5dB | |||||
RIN21.4 OMA | dB/Hz | -136 | ||||
Optical Extinction Ratio | ER | dB | 3.5 | |||
Optical Return Loss Tolerance | ORL | dB | 21.4 | |||
Transmitter and dispersion eye closure (TDECQ), each lane | TDECQ | dB | 3.3 | |||
Average launch power of OFF Transmitter, each lane | dBm | -30 | ||||
Receiver(per lane) | ||||||
Signaling Speed per Lane | GBd | 26.5625 | ||||
Modulation format | PAM4 | |||||
Center wavelength | nm | 1264.5 | 1337.5 | CWDM | ||
Average receive Power per Lane | RXPx | dBm | -8.2 | 4.7 | ||
Receive power, each lane (OMAouter) | dBm | 4.5 | ||||
Receiver reflectance | Rfl | dB | -26 | |||
Receiver sensitivity (OMA outer ), (each lane，max) | dBm | -6 | ||||
Stressed receiver sensitivity (OMAouter) ,each lane | dBm | -3.6 | ||||
VI. Electrical Interface Characteristics
Parameter | Symbol | Unit | Min. | Typ. | Max. | Ref. |
Supply Voltage | VCC | V | 3.135 | 3.3 | 3.465 | |
Supply Current | ICC | mA | 1880 | |||
Power Consumption | W | 6.5 | ||||
Transmitter | ||||||
Differential pk-pk input voltage tolerance | mV | 900 | ||||
Differential termination mismatch | 10% | |||||
SCL and SDA High | VIH | V | 2 | 3.5 | ||
SCL and SDA Low | VIL | V | -0.3 | 0.8 | ||
LPMode, ResetLand ModSelL High | VIH | V | 2 | 3.5 | ||
LPMode, ResetLand ModSelL Low | VIL | V | -0.3 | 0.8 | ||
Differential pk-pk input voltage tolerance | mV | 900 | ||||
Receiver | ||||||
Differential Output Swing | VRXDIFF | mV | 900 | |||
Differential termination mismatch | 10% | |||||
Near-end Eye height, differential | VEH | mV | 70 | |||
Near-end (Eye symmetry mask width) width | ESMW | UI | 0.2 | |||
Transition time (20% to 80%) | Tr,Tf | ps | 9.5 | |||
INTL Output Voltage High | VOH | V | 2 | 3.5 | ||
INTL Output Voltage Low | VOL | V | 0 | 0.8 | ||
IIC communication | ||||||
IIC Clock frequency | - | KHZ | / | 400 | 1000 | |
clock stretching | - | us | / | / | 500 | |
Data hold time | - | ns | 300 | / | / | |
VII. Digital Diagnostic Functions
VIII. Recommended Interface Circuit
Host Board Power Supply Filtering: Any voltage drop across a filter network on the host is counted against the host DC set point accuracy specification. Inductors with DC Resistance of less than 0.1 Ohm should be used in order to maintain the required voltage at the Host Edge Card Connector. Figure is the suggested transceiver/host interface.
Recommended Host Board Power Supply Filtering
IX. Mechanical Specifications (Unit: mm)
Product Features
l 
Up to 26.5625Gbps data rate per channel by PAM4 modulation
l 4 duplex channels transmitters and receivers
l 4x26.5625 GBd PAM4 EML lasers
l Single +3.3V power supply
l SFF-8636 management interface
l Hot-pluggable QSFP56 form factor
l LC connector
l Low power dissipation:<6.5W
l QSFP+ 28Gb/s compliant
l Operating temperature range: 0℃ ~ +70 ℃
l Compliant with ROHS
Applications | Compliance |
200GBASE-FR4 Ethernet. | QSFP56 MSA. |
Switch & Router Connections. | IEEE802.3bs |
Data Center 200GE 2km SMF links. | CMIS V4.0 |
Other 200G Interconnect Requirements. |
Ordering Information
Part NO. | Bit Rate (Gbps) | Laser (nm) | Distance (km) | Media | DDMI | Connector | Temp（℃） |
FSCRLE31-K02C | 212.5 | 1310 | 2 | SMF | YES | duplex LC | 0~70 |