Ascent Communication Technology

6.25G SFP+ SR 850 nm 300 m

Ascent’s DDM SFP+ transceivers are designed for use in 6.25 Gigabit Ethernet links with distances up to 300 m over multi-mode fiber. These transceivers include a PIN photo detector diode and VSCEL transmitter. Digital diagnostic functions are available via a 2-wire interface.

• Supports up to 6.25 Gb/s bit rates with DDM

• Up to 300 m transmission distance on MMF

• VSCEL transmitter and PIN photo-detector

• Metal enclosure, for lower EMI

• 2-wire interface with integrated digital diagnostic monitoring

• Hot-pluggable SFP+ footprint

• Specifications compliant with SFF 8431 and SFF 8472

• Compliant with SFP+ MSA

• Single 3.3 V power supply

Absolute Maximum Ratings

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Maximum Supply Voltage	Vcc	3.15	‑	3.46	V
Storage Temperature	TS	‑40	‑	85	°C
Case Operating Temperature	Tcase	0	‑	70	°C	Commercial
Case Operating Temperature	Tcase	‑40	‑	85	°C	Industrial

Electrical Characteristics

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Supply Voltage	Vcc	3.15	3.3	3.46	V
Supply Current	Icc			300	mA
Transmitter
Input Differential Impedance	Rin		100		Ω	1
Differential Data Input Swing	Vin,pp	180		700	mV
Transmit Disable Voltage	V_DIS	Vcc‑1.3		Vcc	V
Transmit Enable Voltage	V_EN	Vee		Vee+ 0.8	V	2
Transmit Disable Assert Time				10	us
Receiver
Differential Data Output Swing	Vout,pp	300		850	mV	3
Data Output Rise Time	tr	28			ps	4
Data Output Fall Time	tf	28			ps	4
LOS Fault	V_LOS fault	Vcc‑1.3		V_CCHOST	V	5
LOS Normal	V_LOS norm	Vee		Vee+0.8	V	5

Notes:

1. Connected directly to TX data input pins. AC coupled thereafter.

2. Or open circuit.

3. Into 100 Ω differential termination.

4. 20 % to 80 %.

5. Loss Of Signal is LVTTL. Logic 0 indicates normal operation; logic 1 indicates no signal detected.

Optical Characteristics

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Transmitter
Average Output Power	P_OUT	‑6		‑1	dBm	1
Optical Wavelength	λ	830		860	nm
Spectral Width (RMS)	σ			0.85	nm
Optical Extinction Ratio	ER	3.5			dB
RIN	RIN			‑128	dB/Hz
Receiver
Rx Sensitivity	R_SEN			‑12	dBm	2
Input Saturation Power (Overload)	P_SAT	‑1			dBm
Input Optical Wavelength	λC	830		860	nm
LOS De ‑Assert	LOSD			‑13	dBm
LOS Assert	LOSA	‑30			dBm
LOS Hysteresis		0.5	1.0		dB