Ascent Communication Technology

40/100G SFP28 SWDM4 100m

The QSFP28 Bi-Directional transceiver is a high-performance optical module designed for 40G and 100G Ethernet applications over multimode fiber. Supporting transmission distances of up to 70 m on OM3 and 100 m on OM4, the module enables cost-effective high-speed connectivity while allowing reuse of existing duplex LC fiber infrastructure, making it ideal for data center and enterprise network deployments. The module utilizes dual-wavelength VCSEL technology (850 nm / 910 nm) with bi-directional transmission over a single LC fiber pair. Internally, it converts multiple electrical lanes into PAM4 2×50 Gb/s or NRZ channels, delivering an aggregate bandwidth of up to 100 Gb/s. The integrated clock and data recovery (CDR) ensures stable signal integrity, while the QSFP28 electrical interface complies with industry standards for seamless system integration. Designed for high-density environments, the transceiver features low power consumption, hot-pluggable QSFP28 form factor, and digital diagnostic monitoring (DDM) for real-time performance visibility. With its compact design, reliable operation, and compatibility with existing cabling systems, the module provides an efficient solution for switch-to-switch interconnects, data aggregation, and high-speed optical links in modern data center and telecom networks.

·       Compliant to the 40/100GbE XLPPI electrical specification per IEEE 802.3bm
·       Compliant to QSFP28 SFF-8636 Specification and QSFP28 MSA
·       Aggregate bandwidth of > 100Gbps
·       Dual wavelength VCSEL bi-directional optical interface, PAM4 2 × 50-Gb/s or NRZ 2x20G 850nm/910 nm
·       Capable of over 70m transmission on OM3 Multimode Fiber (MMF) and 100m on OM4 MMF
·       Single +3.3V power supply operating
·       With digital diagnostic functions
·       Temperature range 0°C to 70°C
·       RoHS Compliant Part
·       Utilizes a standard LC duplex fiber cable allowing reuse of existing cable infrastructure

Absolute Maximum Ratings

Parameter	Symbol	Min.	Max.	Unit
Storage Temperature	T_S	-40	+85	°C
Supply Voltage	V_CCT, R	-0.5	4.0	V
Relative Humidity	RH	0	85	%

Recommended Operating Conditions

Parameter	Symbol	Min.	Typ.	Max.	Unit
Operating Case Temperature	T_C	0		+70	°C
Power Supply Voltage	V_CCT, R	+3.13	3.3	+3.47	V
Power Supply Current	I_CC			1000	mA
Max Power Consumption	PD			3.5	W

Optical Characteristics

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Transmitter
Optical Wavelength CH1	λ	832	850	868	nm
Optical Wavelength CH2	λ	882	910	918	nm
RMS Spectral Width	Pm		0.5	0.65	nm
Average Optical Power per Channel	Pavg	-6	-1	+4.0	dBm
Laser Off Power Per Channel	Poff			-30	dBm
Optical Extinction Ratio	ER	3.0			dB
Relative Intensity Noise	Rin			-128	dB/HZ	1
Optical Return Loss Tolerance				12	dB
Receiver
Optical Center Wavelength CH1	λ	882	910	918	nm
Optical Center Wavelength CH2	λ	832	850	868	nm
Receiver Sensitivity per Channel	R			-8	dBm
Maximum Input Power	PMAX	+0.5			dBm
Receiver Reflectance	Rrx			-15	dB
LOS De-Assert	LOSD			-10	dBm
LOS Assert	LOSA	-30			dBm
LOS Hysteresis	LOSH	0.5			dB

Note1: 12dB Reflection.

Electrical Characteristics (T_OP = 0 to 70 °C, V_CC = 3.13 to 3.47 Volts)

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Data Rate per Channel			25.78125/ 10.3125		Gbps
Power Consumption		-	2.5	3.5	W
Supply Current	Icc		0.75	1.0	A
Control I/O Voltage-High	VIH	2.0		Vcc	V
Control I/O Voltage-Low	VIL	0		0.7	V
Inter-Channel Skew	TSK			150	Ps
RESETL Duration			10		Us
RESETL De-assert time				100	ms
Power On Time				100	ms
Transmitter
Single Ended Output Voltage Tolerance		0.3		4	V	1
Common mode Voltage Tolerance		15			mV
Transmit Input Diff Voltage	VI	120		1200	mV
Transmit Input Diff Impedance	ZIN	80	100	120
Data Dependent Input Jitter	DDJ			0.1	UI
Data Input Total Jitter	TJ			0.28	UI
Receiver
Single Ended Output Voltage Tolerance		0.3		4	V
Rx Output Diff Voltage	Vo		600	800	mV
Rx Output Rise and Fall Voltage	Tr/Tf	12			ps	1
Total Jitter	TJ			0.7	UI
Deterministic Jitter	DJ			0.42	UI