Ascent Communication Technology

100G QSFP28 PSM4 1310 nm 2 km

Ascent’s QSFP28 100G PSM4 transceiver module is designed to meet the requirements of optical fiber interface for 2 km reach over eight single-mode fibers.

• Hot Pluggable QSFP form factor

• Support 25.78125Gb/s per channel and 103.1Gb/s aggregate bit rate

• Power dissipation < 3.5W

• 3.3V power supply voltage

• Case Operating Temperature: 0 °C to +70 °C

• Up to reach 2 km on Single-Mode MPO (APC 8-degree) connector receptacle

• 4 channels 1310 nm DFB

• 4 channels PIN photo detector array

• Internal CDR circuits on both receiver and transmitter channels

• RoHS-6 compliance

Absolute Maximum Ratings

Parameter	Symbol	Min.	Max.	Unit	Note
Storage Temperature	T_S	‑40	+95	°C
Case Operating Temperature (Commercial)	T_O	0	+70	°C
Relative Humidity ‑ Storage	RH_S	0	95	%
Relative Humidity ‑ Operating	RH_O	0	85	%
Supply Voltage	V_CC	‑0.3	3.6	V

Operating conditions

Parameter	Symbol	Min	Typ.	Max	Unit	Note
Case Operating Temperature	Tcase	0	‑	+70	°C
DC Supply Voltage	V_CC	3.135	‑	3.465	V
Module Supply Current	I_IN	‑	‑	1000	mA

Electrical Characteristics

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Transmitter
Differential Data input Swing	VIN	180	‑	900	mV
Tx Differential Input Impendence	Zin	90	100	110	Ω
Tx Differential Output Impendence	Zout	45	50	55	Ω
ResetL Disable Voltage	Vr	2.0	‑	V_CC+0.3	V
ResetL Enable Voltage	VrEN	0	‑	0.8	V
ModSelL Disable Voltage	Vm	2.0	‑	Vcc+0.3	V
ModSelL Enable Voltage	VmEN	0	‑	0.8	V
Receiver
Differential Data Output Swing	VOUT	180	‑	900	mV
Rx Differential Output Impendence	ZOUT	90	100	110	Ω
IntL Assert Voltage	VInt	V_CC‑0.5	‑	V_CC+0.3	V
IntL De‑assert Voltage	VDInt	0	‑	+0.4	V

Optical Specifications

Parameter	Symbol	Min.	Typ.	Max.	Units	Notes
Transmitter
Signal Rate each Lane	25.78125 ppm ± 100ppm				Gbps
Lane Wavelength	L0	1295	1310	1325	nm
	L1	1295	1310	1325	nm
	L2	1295	1310	1325	nm
	L3	1295	1310	1325	nm
Side Mode Suppression Ratio	SMSR	30			dB
Average Launch Power each Lane	P_avg	‑9.4		2.0	dBm
Optical Modulation Amplitude each Lane	OMA			2.2	dBm	1
Transmitter and Dispersion Penalty each Lane	TDP			2.9	dB
Eye Mask Coordinates: X1, X2, X3, Y1, Y2, Y3	{0.31, 0.4, 0.45, 0.34, 0.38, 0.4}					2
Average Launch Power of OFF Transmitter each Lane				‑30	dBm
Extinction Ratio	ER	3.5			dB
Spectral Width (20 dB)				1	nm
Transmitter Reflectance				‑12	dB
Optical Return Loss Tolerance				20	dB
Receiver
Signal Speed per Lane	25.78125 ppm ± 100 ppm				Gbps
Lane Wavelength	L0	1295	1310	1325	nm
	L1	1295	1310	1325	nm
	L2	1295	1310	1325	nm
	L3	1295	1310	1325	nm
Damage Threshold each Lane	THd			3.0	dBm	3
Average Receive Power each Lane		‑12.66		2.0	dBm
Receiver Reflectance				‑26	dB
Sensitivity OMA each Lane [1]	Sen			‑12.1	dBm	4
Stressed Receiver Sensitivity (OMA), each Lane				‑8.8	dBm
LOS Assert	LOSA		‑18
LOS De‑Assert	LOSD		‑16
LOS Hysteresis	LOSH	0.5		3
Vertical Eye Closure Penalty	VECP	1.9			dB	5
Stressed Eye J2 Jitter	J2		0.27		UI
Stressed Eye J4 Jitter	J4		0.39		UI

Notes:

1. Even if the TDP < 1 dB, the OMA min must exceed the minimum value specified here.

2. Hit ratio of 5E‑5, per IEEE.

3. The receiver shall be able to tolerate, without damage, continuous exposure to a modulated optical input signal having this power level on one lane. The receiver does not have to operate correctly at this input power.

4. Measured with conformance test signal at receiver input for BER = 5E‑5 BER.

5. Vertical eye closure penalty and stressed eye jitter are test conditions for measuring stressed receiver sensitivity. They are not characteristics of the receiver

Digital Diagnostics

Parameter	Symbol	Spec	Units	Condition/Notes
Temperature	Te	±3	°C
Voltage	Vcc	±5 %	V
IBias	BIAS	±10 %	mA
Rx power	Rx‑pwr	±2	dBm
Tx power	Tx‑pwr	±2	dBm