Ascent Communication Technology

400G QSFP112 SR4 850 nm 100 m

Ascent’s 400 Gbps QSFP112 SR4 transceiver is suitable for 400G ethernet and data center interconnect applications. It supports link lengths of up to 100m over MMF with MTP/MPO-12 connector. This transceiver is compliant with QSFP112 MSA, CMIS 4.0 Interface and 400GAUI-4 standards.

• 4x100G PAM4 retimed 400GAUI-4 electrical interface

• MPO-12 APC connector

• 4 channel VCSEL arrays and 4 channels PIN photo detector arrays

• Maximum link length of 60 m on OM3 or 100 m on OM4

• Hot-pluggable QSFP112 form factor

• Compliant with QSFP112_MSA_Specification_Rev2.1.1

• Compliant with CMIS 5.2

• Compliant with IEEE 802.3db

• Compliant with IEEE 802.3ck

• Less than 8W in temperature range of 0 to 70°C

Absolute Maximum Ratings

Parameter	Symbol	Min.	Max.	Unit
Storage Temperature	Ts	‑40	85	°C
Case Operating Temperature	Top	0	70	°C
Relative Humidity (non‑condensation)	RH	15	85	%
Supply Voltage	Vcc	‑0.5	3.6	V
Receiver Damage Threshold, per Lane	PRdmg	5		dBm

Operating Environments

Parameter	Symbol	Min.	Max.	Unit
Operating Case Temperature	Top	0	70	°C
Relative Humidity(non‑condensing)	RH	15	85	%
Power Supply Voltage	Vcc	3.135	3.465	V
Total Power Consumption1	Pc	‑	8	W
Supply Current per end			2.55	A
Bit Rate	BR		425	Gbps
Fiber Length on OM3 MMF			60	m
Fiber Length on OM4 MMF			100	m
I2C Clock Frequency	0		400	kHz

Note:

Under condition of 3.465V operating supply voltage, and 70°C case temperature.

Optical Transmitter

Parameter		Symbol	Min.	Typ.	Max.	Unit
Data Rate per Lane		DR		53.125		GBd
Modulation Format			PAM4
Center Wavelength¹		y	840	860	868	nm
RMS Spectral Width		σ			0.6	nm
Average Launch Power, each Lane		Pavg	‑4.6		4	dBm
Optical Power OMA, each Lane, Max.		POMA	3.5			dBm
OMAouter, each Lane, Min.	max (TECQ, TDECQ) <1.8 dB		max [‑2.6, max(TECQ, TECQ) – 4.4]			dBm
OMAouter, each Lane, Min.	1.8 < max (TECQ, TDECQ) < 4.4 dB		max [‑2.6, max(TECQ, TECQ) – 4.4]			dBm
Transmitter and Dispersion Eye Closure (TDECQ), each Lane		TDECQ			4.4	dB
Transmitter Eye Closure for PAM4 (TECQ), each Lane		TECQ			4.4	dB
Extinction Ratio		ER	2.5			dB
Transmitter Power Excursion, each Lane					2.3	dBm
Optical Return Loss Tolerance		ORLT			14	dB
Optical Power for TX DISABLE					‑30	dBm
Encircled fluxb²			≥86% at 19 µm ≤30% at 4.5 µm

Notes:

1. Defined according to the performance of the laser used.

2. Measured into type A1a.2 or type A1a.3, or A1a.4, 50 um fiber, in accordance with IEC 61280‑1‑

Optical Receiver

Parameter		Symbol	Min.	Typ.	Max.	Unit	Note
Data Rate per Lane		BR		53.125		GBd
Modulation Format			PAM4
Center Wavelength		y	842	850	948	nm
Damage Threshold			5			dBm
Average Receive Power, each Lane			–6.4		4	dBm
Receive Power, each Lane (OMAouter)					3.5	dBm
Receiver Reflectance		Rr			– 15	dB
Receiver Sensitivity, each Lane			RS = max (‑4.6, TECQ – 6.4)			dBm	1
Stressed Receiver Sensitivity, each Lane					–2.0	dBm
Rx LOS	Assert		‑15			dBm
	De‑assert				‑7.5	dBm
	Hysteresis		0.5		5	dB

Notes:

1. Receiver sensitivity is informative and is defined for a transmitter with a value of TECQ. Measured with conformance test signal at TP3 for BER = 2.4E‑4 Pre‑FEC.

Electrical Specification

Parameters	Min.	Typ.	Max.	Unit
Pre FEC Bit Error Ratio			2.4E‑4
Post FEC Bit Error Ratio			1E‑12
Transmitter (each Lane)
Differential pk‑pk Input Voltage Tolerance	750			mV
Differential Termination Mismatch			10	%
Eye Height	10			mV
Common‑Mode to Differential‑Mode Return Loss	IEEE802.3ck Equation (120G– 1)			dB
Vertical Eye Closure			12	dB
Effective Return Loss	7.3			dB
Transition Time	10			ps
Receiver (each Lane)
Differential data output swing	300		900	mVpp
Differential Termination Mismatch			10	%
Eye Height	15			mV
Vertical Eye Closure			12	dB
Common‑Mode to Differential‑Mode Return Loss	IEEE802.3ck Equation (120G– 1)
Effective Return Loss	8.5			dB
Transition Time	8.5			ps