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Fiber Cable Assemblies.

100G QSFP28 PSM4

100G-QSFP28-PSM4 is a Four-Channel, Pluggable, Parallel, Fiber-Optic QSFP28 Transceiver for 100G Ethernet Applications. The QSFP28 full-duplex optical module offers 4 independent transmit and receive channels, each capable of 26Gbps operation for an aggregate data rate of 104Gbps 2km using single mode fiber. 100G-QSFP28-PSM4 are designed to operate over single mode fiber systems using 1310nm DFB laser array. An optical fiber ribbon cable with an MPO/MTPTM connector can be plugged into the QSFP28 module receptacle. Huihongfiber QSFP28 PSM4 is one kind of parallel transceiver which provides increased port density and total system cost savings.

100G QSFP28 PSM4 Features
Four-channel full-duplex transceiver modules
Transmission data rate up to 26Gbit/s per channel
Up to 2km transmission of single mode fiber
Low power consumption <3.5W
Operating case temperature 0°C to +70°C
3.3V power supply voltage
RoHS 6 compliant
Hot Pluggable QSFP28 form factor
Single MPO connector receptacle
Built-in digital diagnostic function

100G QSFP28 PSM4 Applications
100G Ethernet
Proprietary High Speed Interconnections
Data center

Absolute Maximum Ratings
The operation in excess of any absolute maximum ratings might cause permanent damage to this module.

Parameter Symbol Min Max Unit Note
Storage Temperature TST -40 85 degC
Relative Humidity(non-condensing) RH 0 85 %
Operating Case Temperature TOPC 0 70 degC
Supply Voltage VCC -0.3 3.6 V
Input Voltage Vin -0.3 Vcc+0.3 V

Recommended Operating Conditions and Supply Requirements

Parameter Symbol Min Typical Max Unit
Operating Case Temperature TOPC 0 70 degC
Power Supply Voltage VCC 3.13 3.3 3.47 V
Power Consumption 3.5 W
Data Rate DR 25.78125 Gbps
Data Speed Tolerance ∆DR -100 +100 ppm
Link Distance with G.652 D 0 2 km

Optical Characteristics
All parameters are specified under the recommended operating conditions with PRBS31 data pattern unless otherwise specified.

Symbol Min Typical Max Unit Notes
λC 129


1310 132


nm 1
λrms 3.5 nm 1
PAVG -5 -0.5 +2.5 dBm
POMA -5 -0.5 +2.5 dBm 1
Ptx,diff 5.0 dB
between any two lanes
Launch Power in OMA minus

Transmitter and Dispersion Penalty

(TDP), each Lane



-2.3 dBm 1
Rise/Fall Time Tr/Tf ps
Extinction Ratio ER 3.5 dB
Relative Intensity Noise Rin dB/Hz
Optical Return Loss Tolerance TOL dB
Transmitter Reflectance RT dB
Transmitter Eye Mask Margin EMM 10 % 2
Average Launch Power OFF

Transmitter, each Lane

Poff dBm
Transmitter Eye Mask Definition

{X1, X2, X3, Y1, Y2, Y3}




0.43, 0.26,



Parameter Symbol Min Typical Unit Notes
Center Wavelength λC 1290 1310 nm
Damage Threshold THd +3 dBm
Overload, each lane OVL +2 dBm
Receiver Sensitivity in OMA, each Lane SEN dBm 3
Signal Loss Assert Threshold LOSA -30 dBm
Signal Loss Deassert Threshold LOSD dBm
LOS Hysteresis LOSH 0.5 dB
Optical Return Loss ORL dBm


  1. Transmitter wavelength, RMS spectral width and power need to meet the OMA minus TDP specs to guarantee link performance.
  2. The eye diagram is tested with 1000 waveform.
  3. Measured with conformance test signal at receiver input for BER = 1×10-12.

Electrical Specifications

Parameter Symbol Min Typical Max Unit
Differential input impedance Zin 90 100 110 ohm
Differential Output impedance Zout 90 100 110 ohm
Differential input voltage amplitude ΔVin 300 1100 mVp-p
Differential output voltage amplitude ΔVout 500 800 mVp-p
Bit Error Rate BR E-12
Input Logic Level High VIH 2.0 VCC V
Input Logic Level Low VIL 0 0.8 V
Output Logic Level High VOH VCC-0.5 VCC V
Output Logic Level Low VOL 0 0.4 V

Pin Descriptions

PIN Logic Symbol Name/Description
1 GND Ground
2 CML-I Tx2n Transmitter Inverted Data Input
3 CML-I Tx2p Transmitter Non-Inverted Data output
4 GND Ground
5 CML-I Tx4n Transmitter Inverted Data Input
6 CML-I Tx4p Transmitter Non-Inverted Data output
7 GND Ground
8 LVTLL-I ModSelL Module Select
9 LVTLL-I ResetL Module Reset
10 VccRx ﹢3.3V Power Supply Receiver
11 LVCMOS-I/O SCL 2-Wire Serial Interface Clock
12 LVCMOS-I/O SDA 2-Wire Serial Interface Data
13 GND Ground
14 CML-O Rx3p Receiver Non-Inverted Data Output
15 CML-O Rx3n Receiver Inverted Data Output
16 GND Ground
17 CML-O Rx1p Receiver Non-Inverted Data Output
18 CML-O Rx1n Receiver Inverted Data Output
19 GND Ground
GND Ground 1
CML-O Rx2n Receiver Inverted Data Output
CML-O Rx2p Receiver Non-Inverted Data Output
GND Ground 1
CML-O Rx4n Receiver Inverted Data Output 1
CML-O Rx4p Receiver Non-Inverted Data Output
GND Ground 1
LVTTL-O ModPrsL Module Present
LVTTL-O IntL Interrupt
VccTx +3.3 V Power Supply transmitter 2
Vcc1 +3.3 V Power Supply 2
LVTTL-I LPMode Low Power Mode
GND Ground 1
CML-I Tx3p Transmitter Non-Inverted Data Input
CML-I Tx3n Transmitter Inverted Data Output
GND Ground 1
CML-I Tx1p Transmitter Non-Inverted Data Input
CML-I Tx1n Transmitter Inverted Data Output
GND Ground 1


  1. Module circuit ground is isolated from module chassis ground within the module. GND is the symbol for signal and supply (power) common for QSFP28 modules.
  2. The connector pins are each rated for a maximum current of 500mA.

ModSelL Pin
The ModSelL is an input pin. When held low by the host, the module responds to 2-wire serial communication commands. The ModSelL allows the use of multiple QSFP28 modules on a single 2-wire interface bus. When the ModSelL is “High”, the module will not respond to any 2-wire interface communication from the host. ModSelL has an internal pull-up in the module.
ResetL Pin
Reset. LPMode_Reset has an internal pull-up in the module. A low level on the ResetL pin for longer than the minimum pulse length (t_Reset_init) initiates a complete module reset, returning all user module settings to their default state. Module Reset Assert Time (t_init) starts on the rising edge after the low level on the ResetL pin is released. During the execution of a reset (t_init) the host shall disregard all status bits until the module indicates a completion of the reset interrupt. The module indicates this by posting an IntL signal with the Data_Not_Ready bit negated. Note that on power up (including hot insertion) the module will post this completion of reset interrupt without requiring a reset.
LPMode Pin
Huihongfiber PSM4 operate in the low power mode (less than 1.5 W power consumption) This pin active high will decrease power consumption to less than 1W.
ModPrsL Pin
ModPrsL is pulled up to Vcc on the host board and grounded in the module. The ModPrsL is asserted “Low” when the module is inserted and deasserted “High” when the module is physically absent from the host connector.
IntL Pin
IntL is an output pin. When “Low”, it indicates a possible module operational fault or a status critical to the host system. The host identifies the source of the interrupt by using the 2-wire serial interface. The IntL pin is an open collector output and must be pulled up to Vcc on the host board.
Power Supply Filtering
The host board should use the power supply filtering shown in Figure1.

Figure1. Host Board Power Supply Filtering
Optical Interface Lanes and Assignment
The optical interface port is a male MPO connector .The four fiber positions on the left as shown in Figure 2, with the key up, are used for the optical transmit signals (Channel 1 through4). The fiber positions on the right are used for the optical receive signals (Channel 4 through 1). The central four fibers are physically present.

Figure 2. Optical Receptacle and Channel Orientation
Diagnostic Monitoring Interface
Digital diagnostics monitoring function is available on all Huihongfiber QSFP28 PSM4. A 2-wire serial interface provides user to contact with module. The structure of the memory is shown in Figure 3. The memory space is arranged into a lower, single page, address space of 128 bytes and multiple upper address space pages. This structure permits timely access to addresses in the lower page, such as Interrupt Flags and Monitors. Less time critical time entries, such as serial ID information and threshold settings, are available with the Page Select function. The interface address used is A0xh and is mainly used for time critical data like interrupt handling in order to enable a one-time-read for all data related to an interrupt situation. After an interrupt, IntL, has been asserted, the host can read out the flag field to determine the affected channel and type of flag.

Parameter Symbol Min Max Unit Notes
Temperature monitor absolute error DMI_Temp -3 +3 degC Over operating temp
Supply voltage monitor absolute error DMI _VCC -0.1 0.1 V Full operating range
Channel RX power monitor absolute error DMI_RX -3 3 dB Per channel
Channel Bias current monitor DMI_Ibias -10% 10% mA Per channel
Channel TX power monitor absolute error DMI_TX -3 3 dB Per channel

Figure 3

EEPROM Serial ID Memory Contents:




Name of Field Description Value(Hex)
Base ID Fields
128 Identifier QSFP28 0E
129 Extended Identifier 3.5W max. power consumption CC
130 Connector type MPO Fiber Connector 0C
131 Transceiver Application supported Reserved 80
132 0
133 0
134 Reserved 0
135 Intermediate distance 20
136 Shortwave laser w/o OFC


137 Single Mode (SM) 01


138 1200 Mbytes/Sec 80
139 Encoding NRZ 03
140 BR, nominal Nominal bit rate 67
141 Rate Select QSFP28 Rate Select Version 1 0
142 Link Length(Standard SM


2KM 2
143 Link Length(OM3) Not supported 0
144 Link Length(OM2) Not supported 0
145 Link Length(OM1) Not supported 0
146 Link Length(Cooper) Not supported 0
147 Device Tech Uncooled transmitter device;1310nm DFB; No wavelength control; PIN

detector; Transmitter not


148 Vendor Name HUIHONGFIBER
164 Electronic or optical interfaces for InfiniBand                               4x     SDR


Speed(5.0Gb/s),QDR Speed(10Gb/s).

165 Vendor OUI 00 00
166 00 00
167 00 00


168 Vendor PN
184 Vendor Rev REV.1A 31
185 41
186 Wavelength 1310nm 66
187 58
188 Wavelength Tolerance ±15 0B
189 B8
190 Max Case Temp Max Case Temp 70°C 46
191 Check Sum Address 128-190
Extended ID Fields
192 Options Module circuit Rate Select, TX Disable, TX

Fault, LOS, Warning indicators for: Temperature,

VCC, RX power, TX Bias

193 0
194 0
195 DE
196 Vendor SN Serial number provided by vendor(ASCII)
212 Date Code Programmed with manufacturing date
218 Lot Number Programmed with manufacturing lot
220 Diagnostic Monitoring


221 Enhanced Options 0
222 Reserved Reserved Reserved
223 CC_EXT Address 192-222
Vendor Specific ID Fields
224-255 Vendor Specific EEPROM

Mechanical Dimensions
Figure 4.

Attention: To minimize MPO connection induced reflections, an MPO receptacle with 8-degree angled end-face is utilized for this product. A male MPO connector with 8-degree end-face should be used with this product as illustrated in Figure 5.

Figure 5.
This transceiver is specified as ESD threshold 1KV for high speed data pins and 2KV for all others    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 IEC 60825-1:2007. This product complies with 21 CFR 1040.10 and 1040.11 except for deviations pursuant to Laser Notice No. 50, dated (June 24, 2007)