Ascent Communication Technology

25G SFP28 ZR 1310nm 80km

Ascent’s SFP28-25LP-31-80 optical transceiver supports high-speed serial links over Single Mode (SM) optical fiber at signal rates up to 25.78 Gb/s. The product is compliant with Small Form Pluggable industry agreements SFP and SFP28 for mechanical and low-speed electrical specifications. It is intended for use in interconnect applications between data centers with switches, routers, storage equipment etc. The optical performance supports distances up to 80km. The transmitter side of the module incorporates one 1310 nm EML and CDR integrated with the EML driver to transport a 25G Ethernet signal and the receiver side is integrated with SOA and PIN- TIA followed by Rx CDR. As stipulated by the 25G Ethernet standards, Forward Error Correction (FEC) is required to be implemented by the host equipment to ensure reliable system operation. The optical parameters below will provide a bit error ratio (BER) of 5 x 10E-5 for 25G Ethernet. FEC will provide the required quality for secure service. The electrical interface is according to 25GAUI specifications per IEEE 802.3cc. Digital diagnostic monitoring information (DDMI) is present in this module per the requirements of SFF-8472, providing real- time monitoring information of transceiver laser, receiver, and environment conditions over an SFF-8419 2-wire serial interface.

· Supports 25GBASE-ZR

· Supports 25.78G

· Up to 80km transmission on SMF

· EML laser and Integrated SOA & PIN TIA rosa

· High speed I/O electrical interface (25GAUI)

· SFP28 MSA package with duplex LC connector

· Single +3.3V power supply

· Power consumption 2.5 W

· Compliant to IEEE 802.3cc, SFF-8472 ver12.4 and SFF-8431

· Complies with EU Directive 2015/863/EU

· Operating Temperature Range:

Commercial：0°C to +70°C

Absolute Maximum Ratings

Parameter	Symbol	Min.	Typ.	Max.	Unit
Storage Temperature	T_s	-40		85	°C
Operating Relative Humidity	RH	5		95	%
Supply Voltage	V_CC	-0.3		3.6	V

Recommended Operating Conditions

Parameter	Symbol	Min.	Typ.	Max.	Unit	Notes
Operating Case Temperature	Tc	0	-	70	°C
Power Supply Voltage	V_CC	3.13	3.3	3.46	V
Power Supply Current	I_CC	-	-	750	mA
Maximum Power Dissipation	P_D	-	-	2.5	W
Bit Rate	BR		25.78	-	Gb/s
Transmission Distance	TD		-	80	km	Over SMF

Optical Characteristics

Parameter Transmitter	Symbol	Min.	Typ.	Max.	Unit	Notes
Center Wavelength	λ	1295	-	1310	nm
Average Launch Power	Pav	2	-	7	dBm	1
Optical Modulation Amplitude	OMA	2	-	8	dBm
Average Output Power (Laser Turn off)	POUT-OFF	-	-	30	dBm
Side Mode Suppression Ratio	SMSR	30	-	-	dB
RIN20OMA	RIN	-	-	-130	dB/Hz
Extinction Ratio	ER	8	-	-	dB
Transmitter and dispersion penalty (TDP)		-	-	2.7	dB
Optical Eye Mask	IEEE 802.3 cc					2
Receiver
Center Wavelength	λc	1295	-	1310	nm
Receiver sensitivity	RSEN			-28	dBm	3
LOS Assert	LOS_A	-40	-		dBm
LOS De-assert	LOS_D	-	-	-29	dBm
LOS Hysteresis	LOSH	0.5	-	5	dB

Note:

1. The optical power is launched into SMF. Average launch power (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.

2. Measured with a PRBS 231-1 test pattern @25.78125, Hit ratio≤5E-5.

3. Measured with a PRBS 231-1 test pattern @25.78125 Gb/s, BER≤5E-5.

Electrical Characteristics

High-Speed Signal: Compliant to CEI-28G-VSR

Low-Speed Signal: Compliant to SFF-8419

Parameter		Symbol	Min.	Typ.	Max.	Unit	Notes
Transmitter (Module Input)
Differential Data Input Amplitude		VIN,P-P	-	-	900	mVpp
Differential Impedance			90	100	110	Ω
Tx_Disable	Normal Operation	VIL	-0.3	-	0.8	V
Tx_Disable	Laser Disable	VIH	2.0	-	V_CC+0.3	V
Receiver (Module Output)
Differential Data Output Amplitude
Differential Termination Mismatch(1MHZ)
Differential Impedance
Rx_LOS	Normal Operation	VOL	-0.3	-	0.4	V
Rx_LOS	Loss Signal	VOH	2	-	VCCHOST	V

Digital Diagnostics

Parameter	Range	Accuracy	Unit	Calibration
Temperature	0 to 70	±3	°C	Internal
Voltage	3.13 to 3.47	±3%	V	Internal
Tx Bias Current Per Lane	0 to 100	±10%	mA	Internal
Tx Output Power Per Lane	2 to 7	±3	dBm	Internal
Rx Power	-28 to -4	±3	dBm	Internal