Ascent Communication Technology

1.25G SFP 1310 nm 20 km

ASCENT’s SFP-AG-LP-31-20 Small Form Factor Pluggable (SFP) transceivers are compatible with the Small Form Factor Pluggable Multi-Sourcing Agreement (MSA). The transceiver consists of five sections: the LD driver, the limiting amplifier, the digital diagnostic monitor, the 1310nm FP laser and the PIN/TIA. The module data link up to 20 km in 9/125 µm Single-mode fiber.

• Up to 1.25 Gb/s data links

• FP laser transmitter and PIN photo-detector

• Up to 20 km on 9/125 µm SMF

• Hot-pluggable SFP footprint

• Duplex LC/UPC type pluggable optical interface

• Low power dissipation

• Metal enclosure, for lower EMI

• RoHS compliant and lead-free

• Single +3.3V power supply

• Support Digital Diagnostic Monitoring interface

• Compliant with SFF-8472

• Switch to Switch Interface

• Gigabit Ethernet

• Switched Backplane Applications

• Router/Server Interface

• Other Optical Links

Absolute Maximum Ratings

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Storage Temperature	T_s	‑40		85	°C
Relative Humidity	R_H	5		95	%
Power Supply Voltage	V_CC	‑0.5		4	V
Signal Input Voltage		‑0.3		V_CC+0.3	V
Receiver Damage Threshold		+5			dBm

Recommended Operating Conditions

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Case Operating Temperature	T_case	0		70	°C	SFP‑AG‑LP‑31‑20
		‑10		80		SFP‑AG‑LP‑31‑20E
		‑40		85		SFP‑AG‑LP‑31‑20A
Power Supply Voltage	V_CC	3.13	3.3	3.47	V
Power Supply Current	I_CC			280	mA
Power Supply Noise Rejection				100	mVp‑p	100 Hz to 1 MHz
Data Rate			1.25/1.25		Gbps	TX Rate/RX Rate
Transmission Distance				20	km
Coupled Fiber	Single‑mode fiber					9/125 µm SMF

Transmitter Specifications

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Average Output Power	P_OUT	‑9		‑3	dBm	1
Extinction Ratio	E_R	9			dB
Center Wavelength	λ_C	1270	1310	1360	nm	FP Laser
Spectrum Bandwidth (RMS)	σ			3.5	nm
Transmitter OFF Output Power	P_Off			‑45	dBm
Differential Line Input Impedance	R_IN	90	100	110	Ω
Output Eye Mask	Compliant with IEEE802.3 z (class 1 laser safety)					2

Note

1. Measure at 2^7‑1 NRZ PRBS pattern.

2. Transmitter eye mask definition

Receiver Specifications

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Input Optical Wavelength	λ_IN	1270		1610	nm	PIN‑TIA
Receiver Sensitivity	P_IN			‑20	dBm	1
Input Saturation Power (Overload)	P_SAT	‑3			dBm
Loss Of Signal Assert	P_A			‑22	dBm
Loss Of Signal De‑assert	P_D	‑35			dBm	2
LOS Hysteresis	P_A‑P_D	0.5	2	6	dB

Notes

1. Measured with Light source 1310nm, ER=9dB; BER =<10^‑12 @PRBS=2^7‑1 NRZ.

2. When SD De‑Assert, the RX‑LOS output is High‑level (fixed).

Electrical Interface Characteristics

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Transmitter
Total Supply Current	I_CC			A	mA	1
Transmitter Disable Input‑High	V_DISH	2		V_CC+0.3	V
Transmitter Disable Input‑Low	V_DISL	0		0.8	V
Transmitter Fault Input‑High	V_TxFH	2		V_CC+0.3	V
Transmitter Fault Input‑Low	V_TxFL	0		0.8	V
Receiver
Total Supply Current	I_CC			B	mA	1
LOSS Output Voltage‑High	V_LOSH	2		V_CC+0.3	V	LVTTL
LOSS Output Voltage‑Low	V_LOSL	0		0.8	V	LVTTL