Ascent Communication Technology

1.25G SFP BX 3149 20 km

Ascent’s SFP-AGLP-3149-20 transceiver is a flexible solution as an interface for switches, routers, servers, and other optical links.

• Up to 1.25Gb/s data links

• FP laser transmitter for SFP-AG-LP-3149-20

• DFB laser transmitter for SFP-AG-LP-4931-20

• PIN photo-detector

• Up to 20 km on 9/125µm SMF

• Hot-pluggable SFP footprint

• BIDI 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

Absolute Maximum Ratings

Recommended Operating Conditions

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Case Operating Temperature	Tcase	0		70	°C	Commercial
		‑10		80		Extended
		‑40		85		Industrial
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					9/125um SMF

Transmitter Specifications

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Average Output Power	P_OUT	‑9		‑3	dBm	1
Extinction Ratio	ER	9			dB
Center Wavelength	λC	1260	1310	1360	nm	SFP‑AG‑LP‑3149‑20
Center Wavelength		1470	1490	1510		SFP‑AG‑LP‑4931‑20
Side Mode Suppression Ratio	SMSR	30		3	dB	DFB Laser
Spectrum Bandwidth (‑20 dB)	σ			1	nm
Transmitter OFF Output Power	P_OFF			‑45	dBm
Differential Line Input Impedance	RIN	90	100	110	Ω
Output Eye Mask	Compliant with IEEE802.3 z (class 1 laser safety)						2

Notes:

1. Measured at a 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	1470	1490	1510	nm	SFP‑AG‑LP‑3149‑20
Input Optical Wavelength	λ_IN	1290	1310	1330	nm	SFP‑AG‑LP‑4931‑20
Receiver Sensitivity	P_IN			‑20	dBm	1
Input Saturation Power (Overload)	P_SAT	‑3			dBm
Loss Of Signal Assert	P_A	‑35			dBm
Loss Of Signal De‑assert	P_D			‑21	dBm	2
LOS Hysteresis	P_A‑P_D	0.5	2	6	dB

Notes:

1. Measured with light source: 1490 nm (1310 nm), ER = 9 dB; BER ≤10^‑12 @PRBS=2⁷‑1 NRZ.

2. When the LOS is de‑asserted, the RX data± output is the signal output.

Electrical Interface Characteristics

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Transmitter
Total Supply Current	ICC			A	mA	1
Transmitter Disable Input‑High	VDISH	2		Vcc+0.3	V
Transmitter Disable Input‑Low	VDISL	0		0.8	V
Transmitter Fault Input‑High	VTxFH	2		Vcc+0.3	V
Transmitter Fault Input‑Low	VTxFL	0		0.8	V
Receiver
Total Supply Current	ICC			B	mA	1
LOSS Output Voltage‑High	V_LOSH	2		Vcc+0.3	V	LVTTL
LOSS Output Voltage‑Low	V_LOSL	0		0.8	V

Note:

1. A (TX) + B (RX) = 280 mA (Not including termination circuit)

Regulatory Compliance

Feature	Reference	Performance
Electrostatic Discharge (ESD)	IEC/EN 61000‑4‑2	Compatible with standards
Electromagnetic Interference (EMI)	FCC Part 15 Class B EN 55022 Class B (CISPR 22A)	Compatible with standards
Laser Eye Safety	FDA 21CFR 1040.10, 1040.11 IEC/EN 60825‑1, 2	Class 1 laser product
Component Recognition	IEC/EN 60950, UL	Compatible with standards
ROHS	2002/95/EC	Compatible with standards
EMC	EN61000‑3	Compatible with standards