Ascent Communication Technology

25G SFP28 CWDM 10 km(D)

ASCENT’s SFP28 25Gbps CWDM DML Transceiver is a high-performance optical module designed for 10km reach applications supporting data rates from 24.33Gb/s to 25.78Gb/s. Operating over CWDM wavelengths from C27 to C37 on single-mode fiber, it meets the needs of next-generation data center interconnects, 5G fronthaul, and high-speed enterprise networking environments. This compact hot-pluggable SFP28 module is built to comply with industry standards including SFP28 MSA, SFF-8431, and SFF-8432, and is available in both commercial and extended temperature ranges to meet diverse environmental demands. With a low-power 3.3V DC power supply, it helps reduce overall power consumption in dense network infrastructures. The optical assembly features a C27 to C37 DML laser transmitter and a PIN photodiode receiver integrated with a TIA, ensuring low jitter and exceptional bit error rate performance. Engineered for cost-effectiveness, energy efficiency, and long-term reliability, this transceiver is ideal for customers seeking to maximize performance while minimizing operational costs.

· Operating data rate up to 25.78125Gbps

· Up to 10km transmission distance

· Compliant to 25GBASE-LR of the IEEE 802.3cc standard

· High sensitivity Pin photodiode and TIA

· Low EMI

· LC duplex connector

· Hot pluggable 20pin connector

· Low power consumption ≤1.5 W

· Single +3.3V±5% power supply

· Compliant with SFF-8472

· Fully RoHS Compliant

· Case operating temperature

Commercial: 0°C to +70°C

External: -20°C to +85°C

Absolute Maximum Ratings

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Storage Temperature	Ts	-40		85	°C
Relative Humidity	RH	0		95	%

Recommended Operating Conditions

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Case Operating Temperature	Tc	0		70	°C
	Tc	-20		85	°C
Power Supply Voltage	VCC	3.135	3.3	3.465	V
Power Supply				350	mA
Power Consumption				1.5	W
Bit Rate	BR	24.33		25.78125	Gb/s
Bit Error Ratio	BER			5*10^-5
Max Supported Link Length	TD			10	km
	L			10	km

Optical Characteristics(Ta and Vcc= 3.14 to 3.46V)

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Transmitter
Nominal Wavelength	λ	1271,1291,1311,1331,1351,1371			nm
Wavelength Drift	Δλ	-6.5		+6.5	nm
Output Power	Po	0		6	dBm
Average Launch Power	Pav	0		6	dBm
Spectral Width (-20dB)				1	nm
Extinction Ratio	ER	3.5			dB
Side Mode Suppression Ratio	SMSR	30			dB
Average Launch Power of OFF Transmitter	POFF			-30	dBm
Relative Intensity Noise	RIN			-128	dB/Hz
Receiver
Center Wavelength	λC	1271,1291,1311,1331,1351,1371			nm
Receiver Sensitivity(OMA)	RSENSE			-14.4	dBm	1
Receiver Overload (OMA)	Pmax	1			dBm
Optical Return Loss				-26	dB
LOS Assert	LOSA	-30			dBm
LOS De-Assert LOS	LOSD			-17	dBm
LOS Hysteresis		0.5			dB

Note: Measured at 25.78125Gb/s, ER>=3.5dBm, PRBS 2³¹-1 and BER better than or equal to 5E^-5.

Electric Ports Definition

Parameter	Symbol	Min	Typ.	Max	Unit	Note
Transmitter
Input Differential Impedance	RIN		100		Ω
Single-ended Data Input Swing	VIN	90		450	mVp-p
Transmit Disable Voltage	VDIS	2		VCCHOST	V
Transmit Enable Voltage	VEN	VEE		VEE+0.8	V
Transmit Fault Assert Voltage	VFA	2		VCCHOST	V
Transmit Fault De-Assert Voltage	VFDA	VEE		VEE+0.4	V
Receiver
Single-ended Data Output Swing	VOD	200		450	mVp-p
LOS Fault	VLOSFT	2		VCCHOST	V
LOS Normal	VLOSNR	VEE		VEE+0.4	V