Quick Spec:

Part Number: QDD-400G-FR4-A-FL QDD-400G-FR4-A-EXT-FL QDD-400G-FR4-A-IND-FL QDD-400G-FR4-A-FLT

QDD-400G-FR4-A-EXT-FLT QDD-400G-FR4-A-IND-FLT

Form Factor: QSFP56-DD

TX Wavelength: 1310nm

Reach: 2km

Cable Type: SMF

Rate Category: 400GBase

Interface Type: FR4

DDM: Yes

Connector Type: Dual-LC

Arista Compatible QDD-400G-FR4-A-FL Features

• QSFP56-DD MSA compliant

• 4 CWDM lanes MUX/DEMUX design

• 100G Lambda MSA 400G-FR4 Specification compliant

• Up to 2km transmission on single mode fiber (SMF) with FEC

• 8x53.125Gb/s electrical interface (400GAUI-8)

• Data Rate 106.25Gbps (PAM4) per channel.

• Maximum power consumption 12W

• Duplex LC connector

• RoHS compliant

• Operating Case Temperature

  • Standard: 0°C to +70 °C

  • Extended -5°C to +85 °C

  • Industrial -40°C to +85 °C

    Arista Compatible QDD-400G-FR4-A-FL Applications

    
    

• Data Center Interconnect

• 400G Ethernet

• Infiniband interconnects

• Enterprise networking

Arista Compatible QDD-400G-FR4-A-FL General Description

This product is a 400Gb/s Quad Small Form Factor Pluggable-double density (QSFP56-DD) optical module designed for 2km optical communication applications. The module converts 8 channels of 50Gb/s (PAM4) electrical input data to 4 channels of CWDM optical signals and multiplexes them into a single channel for 400Gb/s optical transmission. Reversely, on the receiver side, the module optically de-multiplexes a 400Gb/s optical input into 4 channels of CWDM optical signals, and converts them to 8 channels of 50Gb/s (PAM4) electrical output data.

The central wavelengths of the 4 CWDM channels are 1271, 1291, 1311 and 1331 nm as members of the CWDM wavelength grid defined in ITU-T G.694.2. It contains a duplex LC connector for the optical interface and a 76-pin connector for the electrical interface. To minimize the optical dispersion in the long-haul system, single-mode fiber (SMF) has to be applied in this module. Host FEC is required to support up to 2km fiber transmission.

The product is designed with form factor, optical/electrical connection and digital diagnostic interface according to the QSFP56-DD Multi-Source Agreement (MSA) Type 2. It has been designed to meet the harshest external operating conditions including temperature, humidity and EMI interference.

Arista Compatible QDD-400G-FR4-A-FL Functional Description

The module incorporates 4 independent channels on CWDM4 1271/1291/1311/1331nm center wavelength, operating at 100G per channel. The transmitter path incorporates a quad channel EML driver and EML lasers together with an optical multiplexer. On the receiver path, an optical de- multiplexer is coupled to a 4-channel photodiode array. A DSP basis gearbox is used to convert 8 channels of 25GBaud PAM4 signals into 4 channels of 50GBaud PAM4 signals and also an 8-channel retimer and FEC block are integrated in this DSP. The electrical interface is compliant with IEEE 802.3bs and QSFP56-DD MSA in the transmitting and receiving directions, and the optical interface is compliant to IEEE 802.3bs with duplex LC connector.

A single +3.3V power supply is required to power up this product. All the power supply pins are internally connected and should be applied concurrently. As per MSA specifications the module offers seven low speed hardware control pins (including the 2-wire serial interface): ModSelL, SCL, SDA, ResetL, InitMode, ModPrsL and IntL.

Module Select (ModSelL) is an input pin. When held low by the host, this product responds to 2- wire serial communication commands. The ModSelL allows the use of this product on a single 2- wire interface bus – individual ModSelL lines must be used.

Serial Clock (SCL) and Serial Data (SDA) are required for the 2-wire serial bus communication interface and enable the host to access the memory map.

The ResetL pin enables a complete reset, returning the settings to their default state, when a low

Transceiver Block Diagram

Figure 1. Transceiver Block Diagram

Pin Assignment and Description

The electrical pinout of the QSFP56-DD module is shown in Figure 2 below.

Figure 2. MSA Compliant Connector

Pin Definition

Recommended Power Supply Filter

Absolute Maximum Ratings

It has to be noted that the operation in excess of any individual absolute maximum ratings might cause permanent damage to this module.

Recommended Operating Conditions and Power Supply Requirements

Notes:

1. FEC provided by host system.

2. FEC required on host system to support maximum distance.

Electrical Characteristics

The following electrical characteristics are defined over the Recommended Operating Environment unless otherwise specified.

Notes:

1. With the exception to IEEE 802.3bs 120E.3.1.2 that the pattern is PRBS31Q or scrambled idle.

2. Meets BER specified in IEEE 802.3bs 120E.1.1.

3. DC common mode voltage generated by the host. Specification includes effectsof ground offset voltage.

Optical Characteristics

1. Notes:

2. Average launch power, each lane (min) is informative and not the principal indicator of signal strength. A transmitter with launch power below this value cannot be compliant; however, a value above this does not ensure compliance.

3. Even if the TDECQ < 1.4 dB for an extinction ratio of ≥ 4.5 dB or TDECQ < 1.3 dB for an extinction ratio of < 4.5 dB, the OMAouter (min) must exceed the minimum value specified here.

4. The receiver shall be able to tolerate, without damage, continuous exposure to an optical input signal having this average power level.

5. Average receive power, each lane (min) is informative and not the principal indicator of signal strength. A received power below this value cannot be compliant; however, a value above this does not ensure compliance.

6. Measured with conformance test signal for BER = 2.4x10-4. A compliant receiver shall have stressed receiver sensitivity (OMAouter), each lane values below the mask of Figure 4, for SECQ values between 0.9 and 3.4 dB.

   

   For SECQ 1.4 to 3.4dB

   For SECQ<1.4dB

7. These test conditions are for measuring stressed receiver sensitivity. They are not characteristics of the receiver

   
   

   
   

   
   

   Digital Diagnostic Functions

   The following digital diagnostic characteristics are defined over the normal operating conditions unless otherwise specified.

   
   

   Parameter	Symbol	Min	Max	Units	Notes
   Temperature monitor absolute error	DMI_Temp	-3	3	degC	Over operating temperature range
   Supply voltage monitor absolute error	DMI _VCC	-0.1	0.1	V	Over full operating range
   Channel RX power monitor bsolute error	DMI_RX_Ch	-2	2	dB	1
   Channel Bias current monitor	DMI_Ibias_Ch	- 10%	10%	mA
   Channel TX power monitor bsolute error	DMI_TX_Ch	-2	2	dB	1

   
   

   Notes:

   1. Due to measurement accuracy of different single mode fibers, there could be an additional +/-1 dB fluctuation, or a +/- 3 dB total accuracy.

Mechanical Dimensions

ESD

This transceiver is specified as ESD threshold 1kV for high speed data pins and 2kV for all other electrical input pins, tested per MIL-STD-883, Method 3015.4 /JESD22- A114-A (HBM). However, normal ESD precautions are still required during the handling of this module. This transceiver is shipped in ESD protective packaging. It should be removed from the packaging and handled only in an ESD protected environment.

Laser Safety

This is a Class 1 Laser Product according to EN 60825-1:2014. This product complies with 21 CFR 1040.10 and 1040.11 except for deviations pursuant to Laser Notice No. 50, dated (June 24, 2007).

Caution: Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure.

Licensing

The following U.S. patents are licensed by Finisar to FluxLight, Inc.:

U.S. Patent Nos: 7,184,668, 7,079,775, 6,957,021, 7,058,310, 6,952,531, 7,162,160, 7,050,720