Ascent Communication Technology

25G SFP28 BIDI 80 km

The SFP28 25Gb/s BIDI transceiver is a high-performance, long-reach optical module designed for up to 80 km transmission over single-mode fiber (SMF). Supporting data rates up to 25.78125 Gb/s, the module is compliant with IEEE 802.3cc, SFF-8472, and SFF-8419 standards, making it suitable for high-speed applications such as 25G Ethernet and CPRI links. Its compact SFP28 form factor with a single LC interface enables efficient bidirectional transmission over a single fiber. The transceiver utilizes a high-performance EML transmitter combined with an integrated SOA and PIN/TIA receiver, ensuring excellent optical performance and extended transmission reach. Operating at nominal wavelengths of approximately 1295 nm or 1309 nm, the module supports stable long-distance communication with high sensitivity and low noise characteristics. The electrical interface is compliant with SFI specifications, with AC-coupled high-speed differential signaling for reliable signal integrity. Designed for efficiency and reliability, the module offers low power consumption and supports both commercial and industrial operating environments. It also provides digital diagnostic monitoring (DDM) via a standard I²C interface, enabling real-time monitoring of key parameters such as temperature, voltage, and optical power. With its robust design and long-reach capability, the SFP28 25G BIDI transceiver is ideal for carrier-grade networks, long-distance data links, and next-generation access infrastructure.

· Support data rate up to 25.78125Gb/s

· Hot-Pluggable SFP Footprint and Single LC Connector

· Up to 80km reach for G.652 SMF

· EML TX and Integrated SOA & PIN TIA RX

· Temperature Range:

Commercial: 0°C ~ 70°C

Industrial: -40°C ~ 85°C

· Power consumption

Commercial: 2.2W

Industrial: 2.8W

· RoHS 6 compliance

· Compliant to IEEE 802.3cc, SFF-8472 and SFF-8419

· Complies with EU Directive 2015/863/EU

Absolute Maximum Ratings

Parameter	Symbol	Min.	Typ.	Max.	Unit	Notes
Storage Temperature	Tstg	-40		+85	°C
Operating Case Temperature	T_O	0		70	°C	Commercial
	T_O	-40		85	°C	Industrial
Storage Relative Humidity	R_HS	5		95	%
Operating Relative Humidity	R_HO	5		85	%
DC Supply Voltage	V_CC	0		3.6	V

Recommended Operating Conditions

Parameter	Symbol	Min.	Typ.	Max.	Unit	Notes
Operating Case Temperature	Top	0	-	70	°C	Commercial
Operating Case Temperature	Top	-40		85	°C	Industrial
Power Supply Voltage	V_CC	3.13	3.3	3.47	V
Transmission Distance	TD	-	-	80	km	Over SMF

Electrical Characteristics
High-Speed Signal: Compliant to CEI-25G-VSR
Low-Speed Signal: Compliant to SFF-8431

Parameter		Symbol	Min.	Typ.	Max.	Unit	Notes
Supply Voltage		V_CC	3.135		3.465	V
Supply Current		I_CC			660	mA	Commercial
Supply Current		I_CC			850	mA	Industrial
Power Consumption		P			2.2	W	Commercial
Power Consumption		P			2.8	W	Industrial
Transmitter (Module Input)
Differential Input Resistance		R_R_din	90	100	110	W
Input Differential Voltage		R_V_diff	-	-	900	mVpp
Tx_Disable	Normal Operation	V_IL	-0.3	-	0.8	V
Tx_Disable	Laser Disable	V_IH	2.0	-	V_CC+0.3	V
Receiver (Module Output)
Differential Resistance		T_R_d	90	100	110	Ohm
Output Differential Voltage		T_V_diff	-	-	900	mVpp
Differential Termination Resistance Mismatch		T_R_dm	-	-	10	%
Rx los	Normal Operation	V_OL	-0.3	-	0.4	V
Rx los	Loss Signal	V_OH	2		V_CCHOST	V

Optical Characteristics

Parameter	Symbol	Min.	Typ.	Max.	Unit	Notes
Transmitter
Average Output Power	P_OUT	2		7	dBm	1
Average Output Power(Laser Off)	P_OFF			-30	dBm
Wavelength	λ	1294.53	1295.56	1296.59	nm
Wavelength	λ	1308.09	1309.14	1310.19	nm
Spectrum Bandwidth @ -20dB	Δλ			1	nm
Side mode suppression ratio(SMSR)	SMSR	30			dB
Extinction ratio	ER	8			dB
RIN20OMA	RIN			-128	dB/Hz
Transmitter and dispersion penalty (TDP)				2.7	dB
Receiver
Wavelength	λ	1308.09	1309.14	1310.19	nm
Wavelength	λ	1294.53	1295.56	1296.59	nm
Received Sensitivity	P_IN			-27	dBm	1
Optical Power Overload	P_IN(SAT)	-4			dBm
Damage threshold		3			dBm	2
Rx_LOS of Signal Assert	P_A	-40			dBm
Rx_LOS of Signal De-assert	P_D			-28	dBm
Rx_LOS of Signal Hysteresis	PHy	0.5		5	dB
Optical Return Loss Tolerance	ORLT	20			dB

Notes:

1. Test pattern: PRBS31. BER<5x10^-5.

2. The receiver shall be able to tolerate, without damage, continuous exposure to an optical input signal having this average power level. The receiver does not have to operate correctly at this input power.

Communication Interface Timing Characteristics

Parameter	Symbol	Min.	Typ.	Max.	Unit	Notes
TX_Disable Assert Time	t_off			100	us
TX_Disable Negate Time	t_on			2	ms
Time to Initialize Include Reset of TX_FAULT	t_int			300	ms
TX_FAULT from Fault to Assertion	t_fault			100	us
TX_Disable Time to Start Reset	t_reset	10			us
Receiver Loss of Signal Assert Time	TA,RX_LOS			100	us
Receiver Loss of Signal Deassert Time	Td,RX_LOS			100	us
Rate-Select Chage Time	t_ratesel			10	us