Ascent Communication Technology

25G SFP28 1310 nm 40km

Ascent’s SFP28 transceivers are designed for use in 25G Gigabit Ethernet links with distances up to 40 km over single-mode fiber. These transceivers include an high sensitivity APD photo detector diode and DFB transmitter. Digital diagnostic functions are available via a 2-wire interface. Ascent’s SFP28 transceivers provide a unique enhanced digital diagnostic monitoring interface which allows real-time access to device operating parameters such as transceiver temperature, laser bias current, transmitted optical power, received optical power, and transceiver supply voltage. It also defines a sophisticated system of alarm and warning flags which alerts end users when particular operating parameters are outside of a factory set normal range. Ascent’s 25G SFP28 transceivers are compliant with SFF 8431 and SFF 8472 standards, and offer a convenient solution for high-speed storage area networks, OBSAI and CPRI 10 applications, and LTE optical repeater applications.

· Operating data rate up to 25.78Gbps

· Rate Adaptation

· Up to 40km transmission distance

· High sensitivity APD photodiode and TIA

· LC single connector

· Hot pluggable 20pin connector

· Low power consumption

· Single +3.3V ±5% power supply

· Compliant with SFF-8472 & IEEE 802.3cc

· Fully RoHS Compliant

· Operating Temperature Range:

Commercial：0°C to +70°C

Industrial: -40°C to +85°C

Absolute Maximum Ratings

Parameter	Symbol	Min.	Typ.	Max.	Unit
Storage Temperature	T_s	-40		85	°C
Relative Humidity	RH	5		95	%

Recommended Operating Conditions

Parameter	Symbol	Min.	Typ.	Max.	Unit	Notes
Case Temperature	Tc	0		70	°C	1
Case Temperature		-40		85	°C	2
Power Supply Voltage	V_CC	3.14	3.30	3.46	V
Bit Rate	BR		25.78125		Gbps
Bit Error Ratio	BER			5*10^-5
Max Supported Link Length	L			80	km	Over SMF

Note1, 2: See order information

Optical Characteristics

Parameter Transmitter	Symbol	Min.	Typ.	Max.	Unit	Note
Center Wavelength	λ	1290		1330	nm
Side-mode Suppression Ratio	SMSR	30			dB
Average Optical Power	Pavg	-2		6.0	dBm
Optical Modulation Amplitude	TxOMA	0			dBm
Transmitter and Dispersion Penalty	TDP			2.7	dB
Average Launch Power of OFF Transmitter	Poff			-20	dBm
Extinction Ratio	ER	4		-	dB
Optical Return Loss Tolerance		-		20	dB
Transmitter Reflectance				-26	dB
Receiver
Center Wavelength	λc	1290	-	1330	nm
Damage Threshold		-3			dBm
Receive Power Overload				-5	dBm
Receiver Reflectance				-26	dB
Receiver Sensitivity	S			-19	dBm	1
LOS Assert	LOSA	-30	-		dBm
LOS De-assert	LOSD	-	-	-21	dBm
LOS Hysteresis		0.5			dB

Note:

1. Measured at 25.78Gb/s, ER>4dBm, PRBS 2 31 -1 and BER better than or equal to 5E-5.

Electric Ports Definition

Parameter	Symbol	Min.	Typ.	Max.	Unit	Notes
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

Digital Diagnostics

Parameter	Accuracy	Unit
Internally measured transceiver temperature	+/-3	°C
Internally measured transceiver supply voltage	+/-3	%
Measured Tx bias current	+/-10	%
Measured Tx output power	+/-3	dB
Measured Rx received average optical power	+/-3	dB