Quick Spec:

Arista QDD-400G-SR8-A-FL Datasheet (400GBase, SR8, QSFP56-DD, 850nm, MMF, 100m, MPO24, COM) Fiber Optic Transceiver

Part Number: QDD-400G-SR8-A-FL QDD-400G-SR8-A-EXT-FL QDD-400G-SR8-A-IND-FL QDD-400G-SR8-A-FLT

QDD-400G-SR8-A-EXT-FLT QDD-400G-SR8-A-IND-FLT


Form Factor: QSFP56-DD

TX Wavelength: 850nm

Reach: 70m

Cable Type: MMF

Rate Category: 400GBase

Interface Type: SR8

DDM: Yes

Connector Type: MPO-16


Arista Compatible QDD-400G-SR8-A-FL Features


Arista Compatible QDD-400G-SR8-A-FL General Description

This product is a parallel 400Gb/s Quad Small Form Factor Pluggable--double density (QSFP56-DD) optical module. It provides increased port density and total system cost savings. The QSFP56-DD full-duplex optical module offers 8 independent transmit and receive channels, each capable of 53.125Gb/s operation for an aggregate data rate of 400Gb/s on 100 meters of OM3 multi-mode fiber.


An optical fiber cable with an MTP/MPO-16 connector can be plugged into the QSFP56-DD SR8 module receptacle. Proper alignment is ensured by the guide pins inside the receptacle. The cable usually cannot be twisted for proper channel to channel alignment. Electrical connection is achieved through an QSFP56-DD MSA-compliant edge type connector.


The central wavelengths of all the 8 parallel lanes are 850nm. It contains an optical MPO-16 connector for the optical interface and a 60-pin connector for the electrical interface. Host FEC is required to support up to 70m OM3 multi-mode 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-SR8-A-FL Functional Description

The module incorporates 8 parallel channels, on 850nm Center Wavelength, operating at 50G per channel. The transmitter path incorporates an 8-channel CDR retimer, 2 sets of quad channel VCSEL drivers together with 2 sets of VCSEL arrays. On the receiver path, 2 sets of photodiode arrays optics are coupled with an 8-channel CDR retimer. 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 QSFP56-DD MSA with MPO-16 Optical Connector. Figure 1 shows the functional block diagram of this product.


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.


The ResetL pin enables a complete reset, returning the settings to their default state, when a low level on the ResetL pin is held for longer than the minimum pulse length. During the execution of a reset the host shall disregard all status bits until it indicates a completion of the reset interrupt. The product indicates this by posting an IntL (Interrupt) signal with the Data_Not_Ready bit negated in the memory map. Note that on power up (including hot insertion) the module should post this completion of reset interrupt without requiring a reset.


Initialize Mode (InitMode) is an input signal. It is pulled up to Vcc in the QSFP56-DD module. The InitMode signal allows the host to define whether the QSFP56-DD module will initialize under host software control (InitMode asserted High) or module hardware control (InitMode deasserted Low). Under host software control, the module shall remain in Low Power Mode until software enables the transition to High Power Mode, as defined in the QSFP56-DD Management Interface Specification. Under hardware control (InitMode de-asserted Low), the module may immediately transition to High Power Mode after the management interface is initialized. The host shall not change the state of this signal while the module is present. In legacy QSFP applications, this signal is named LPMode. See SFF-8679 for LPMode signal description.


Module Present (ModPrsL) is a signal local to the host board which, in the absence of a product, is normally pulled up to the host Vcc. When the product is inserted into the connector, it completes the path to ground through a resistor on the host board and asserts the signal. ModPrsL then indicates its present by setting ModPrsL to a “Low” state.


Interrupt (IntL) is an output pin. “Low” indicates a possible operational fault or a status critical to the host system. The host identifies the source of the interrupt using the 2-wire serial interface. The IntL pin is an open collector output and must be pulled to the Host Vcc voltage on the Host board.


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.


Transceiver Block Diagram



image


Figure 1. Transceiver Block Diagram


Pin Assignment and Description

The electrical pinout of the QSFP56-DD module is shown as Figure 2. And Figure 3 shows the optical interface of MPO- 16.



image


Figure 2. MSA Compliant Connector


image

Figure 3. MPO-16 Optical connector Interface


Pin Definition


Pin

Logic

Symbol

Description

Plug Sequence

1


GND

Ground

1B

2

CML-I

Tx2n

Transmitter Inverted Data Input

3B

3

CML-I

Tx2p

Transmitter Non-Inverted Data Input

3B

4


GND

Ground

1B

5

CML-I

Tx4n

Transmitter Inverted Data Input

3B

6

CML-I

Tx4p

Transmitter Non-Inverted Data Input

3B

7


GND

Ground

1B

8

LVTTL-I

ModSelL

Module Select

3B

9

LVTTL-I

ResetL

Module Reset

3B

10


VccRx

+3.3V Power Supply Receiver

2B

11

LVCMOS

-

I/O

SCL

2-wire serial interface clock

3B

12

LVCMOS

-

I/O

SDA

2-wire serial interface data

3B

13


GND

Ground

1B

14

CML-O

Rx3p

Receiver Non-Inverted Data Output

3B

15

CML-O

Rx3n

Receiver Inverted Data Output

3B

16

GND

Ground

1B


17

CML-O

Rx1p

Receiver Non-Inverted Data Output

3B

18

CML-O

Rx1n

Receiver Inverted Data Output

3B

19


GND

Ground

1B

20


GND

Ground

1B

21

CML-O

Rx2n

Receiver Inverted Data Output

3B

22

CML-O

Rx2p

Receiver Non-Inverted Data Output

3B

23


GND

Ground

1B

24

CML-O

Rx4n

Receiver Inverted Data Output

3B

25

CML-O

Rx4p

Receiver Non-Inverted Data Output

3B

26


GND

Ground

1B

27

LVTTL-O

ModPrsL

Module Present

3B

28

LVTTL-O

IntL

Interrupt

3B

29


VccTx

+3.3V Power supply transmitter

2B

30


Vcc1

+3.3V Power supply

2B

31

LVTTL-I

InitMode

Initialization mode; In legacy QSFP applications, the InitMode pad

is called LPMODE

3B



32


GND

Ground

1B

33

CML-I

Tx3p

Transmitter Non-Inverted Data Input

3B

34

CML-I

Tx3n

Transmitter Inverted Data Input

3B

35


GND

Ground

1B

36

CML-I

Tx1p

Transmitter Non-Inverted Data Input

3B

37

CML-I

Tx1n

Transmitter Inverted Data Input

3B

38


GND

Ground

1B

39


GND

Ground

1A

40

CML-I

Tx6n

Transmitter Inverted Data Input

3A

41

CML-I

Tx6p

Transmitter Non-Inverted Data Input

3A

42


GND

Ground

1A

43

CML-I

Tx8n

Transmitter Inverted Data Input

3A

44

CML-I

Tx8p

Transmitter Non-Inverted Data Input

3A

45


GND

Ground

1A

46


Reserved

For future use

3A

47


VS1

Module Vendor Specific 1

3A

48


VccRx1

3.3V Power Supply

2A

49


VS2

Module Vendor Specific 2

3A

50


VS3

Module Vendor Specific 3

3A

51


GND

Ground

1A

52

CML-O

Rx7p

Receiver Non-Inverted Data Output

3A

53

CML-O

Rx7n

Receiver Inverted Data Output

3A

54


GND

Ground

1A

55

CML-O

Rx5p

Receiver Non-Inverted Data Output

3A

56

CML-O

Rx5n

Receiver Inverted Data Output

3A

57


GND

Ground

1A

58


GND

Ground

1A

59

CML-O

Rx6n

Receiver Inverted Data Output

3A

60

CML-O

Rx6p

Receiver Non-Inverted Data Output

3A

61


GND

Ground

1A

62

CML-O

Rx8n

Receiver Inverted Data Output

3A

63

CML-O

Rx8p

Receiver Non-Inverted Data Output

3A

64


GND

Ground

1A

65


NC

No Connect

3A

66


Reserved

For future use

3A

67


VccTx1

3.3V Power Supply

2A

68


Vcc2

3.3V Power Supply

2A

69


Reserved

For Future Use

3A

70


GND

Ground

1A



71

CML-I

Tx7p

Transmitter Non-Inverted Data Input

3A

72

CML-I

Tx7n

Transmitter Inverted Data Input

3A

73


GND

Ground

1A

74

CML-I

Tx5p

Transmitter Non-Inverted Data Input

3A

75

CML-I

Tx5n

Transmitter Inverted Data Input

3A

76


GND

Ground

1A


Recommended Power Supply Filter


image


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.



Parameter

Symbol

Min

Max

Units

Notes

Storage Temperature

TS

-40

85

degC


Operating Case Temperature - Commercial

TOP

0

70

degC


Operating Case Temperature - Industrial

TOP

-40

85

degC


Power Supply Voltage

VCC

-0.5

3.6

V


Relative Humidity (non-condensation)

RH

0

85

%



Recommended Operating Conditions and Power Supply Requirements


Parameter

Symbol

Min

Typical

Max

Units

Notes


Operating Case Temperature


TOP


0



70


degC


Power Supply Voltage

VCC

3.135

3.3

3.465

V


Data Rate, each Lane



26.5625


GBd

PAM4

Data Rate Accuracy


-100


100

ppm


Pre-FEC Bit Error Ratio




2.4x10-4



Post-FEC Bit Error Ratio




1x10-12


1

Link Distance

D

0.5


500

m

2

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.


Parameter

Test Point

Min

Typical

Max

Units

Notes

Power Consumption




11

W


Supply Current

Icc



3.33

A


Transmitter (each Lane)

Signaling Rate, each Lane

TP1

26.5625 ± 100 ppm

GBd


Differential pk-pk Input Voltage Tolerance

TP1a

900



mVpp

1

Differential Termination Mismatch

TP1



10

%


Differential Input Return Loss

TP1

IEEE 802.3-2015 Equation (83E-5)

dB


Differential to Common Mode Input Return Loss


TP1

IEEE 802.3-2015 Equation (83E- 6)


dB


Module Stressed Input Test

TP1a

See IEEE 802.3bs 120E.3.4.1


2

Single-ended Voltage Tolerance Range (Min)

TP1a

-0.4 to 3.3

V


DC Common Mode Input Voltage

TP1

-350


2850

mV

3

Receiver (each Lane)

Signaling Rate, each lane

TP4

26.5625 ± 100 ppm

GBd


Differential Peak-to-Peak Output Voltage

TP4



900

mVpp


AC Common Mode Output Voltage, RMS

TP4



17.5

mV


Differential Termination Mismatch

TP4



10

%



Differential Output Return Loss


TP4

IEEE 802.3-2015 Equation (83E-2)



Common to Differential Mode Conversion Return Loss


TP4

IEEE 802.3-2015 Equation (83E-3)



Transition Time, 20% to 80%

TP4

9.5



ps


Near-end Eye Symmetry Mask Width (ESMW)

TP4


0.265


UI


Near-end Eye Height, Differential

TP4

70



mV


Far-end Eye Symmetry Mask Width (ESMW)


TP4



0.2



UI


Far-end Eye Height, Differential

TP4

30



mV


Far-end Pre-cursor ISI Ratio

TP4

-4.5


2.5

%


Common Mode Output Voltage (Vcm)


TP4


-350



2850


mV


3


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


Parameter

Symbol

Min

Typical

Max

Units

Notes

Transmitter

Center Wavelength

λc

840

850

860

nm


Data Rate, each Lane


26.5625 ± 100 ppm

GBd


Modulation Format


PAM4



RMS Spectral Width

∆λrms



0.6

nm

Modulated

Average Launch Power, each Lane

Pavg

-6


4

dBm

1

Outer Optical Modulation Amplitude (OMAouter), each Lane

Poma

-4



3


dBm

2

Launch Power in OMAouter minus TDECQ, each Lane


--5



dB


Transmitter and Dispersion Eye Closure for PAM4, each Lane


TDECQ




4


dB


Extinction Ratio

ER

3



dB


Optical Return Loss Tolerance

TOL



12

dB


Average Launch Power of OFF Transmitter, each Lane

Poff



-30

dBm


Encircled Flux


≥ 86% at 19 μm

≤ 30% at 4.5μm



Receiver

Center Wavelength

λc

840

850

860

nm


Data Rate, each Lane


26.5625 ± 100 ppm

GBd


Modulation Format


PAM4



Damage Threshold, each Lane

THd

5



dBm

3

Average Receive Power, each Lane


-7.9


4

dBm

4

Receive Power (OMAouter), each Lane




3

dBm


Receiver Sensitivity

(OMAouter), each Lane

SEN



-7

dBm

5

Stressed Receiver Sensitivity

(OMAouter), each Lane

SRS



-3

dBm

6

Receiver Reflectance

RR



-12

dB


LOS Assert

LOSA

-30



dBm


LOS De-assert

LOSD



-12

dBm


LOS Hysteresis

LOSH

0.5



dB


Stressed Conditions for Stress Receiver Sensitivity (Note 7)







Stressed Eye Closure for PAM4 (SECQ), Lane under Test



4



dB


OMAouter of each Aggressor Lane



3


dBm



Notes:

  1. 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 ensurecompliance.

  2. Even if the TDECQ < 1.4 dB, the OMAouter (min) must exceed the minimum value specified here.

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

  4. 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.

  5. Receiver sensitivity (OMAouter), each lane (max) is informative and is defined fora transmitter with SECQ of 0.9 dB.

  6. Measured with conformance test signal for BER = 2.4x10-4.

  7. These test conditions are for measuring stressed receiver sensitivity. They arenot 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 absolute error

    DMI_RX_Ch

    -2

    2

    dB

    1

    Channel Bias current monitor

    DMI_Ibias_Ch

    -

    10%

    10%

    mA


    Channel TX power monitor absolute 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


image


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