Ascent Communication Technology

400G QSFP112 VR4 Transceiver

The 400G QSFP112 VR4 transceiver is a high-performance, short-reach optical module designed for next-generation 400G Ethernet and InfiniBand applications in hyperscale data center environments. Utilizing four parallel optical lanes operating at 106.25Gb/s PAM4, the module delivers an aggregate bandwidth of up to 425Gb/s over multimode fiber, supporting transmission distances of up to 50 meters on OM4 MMF. Its compact QSFP112 Type 1 form factor enables high-density deployment in modern switch, router, and AI cluster architectures. The module incorporates advanced 850nm VCSEL transmitters and PIN receivers with a high-speed 400GAUI-4 electrical interface, providing excellent signal integrity and low latency performance for demanding data center interconnect applications. The optical interface utilizes a standard MPO-12 connector, enabling efficient parallel fiber connectivity for high-speed networking infrastructure. Designed for optimized thermal and EMI performance, the transceiver supports reliable operation in dense networking systems while maintaining low power consumption. Fully compliant with 400G QSFP112 MSA and CMIS 4.0 management interface standards, it supports comprehensive digital diagnostics and control functions for real-time system monitoring and management. Operating from a single +3.3V power supply over a commercial temperature range of 0°C to +70°C, the module is RoHS compliant and designed to meet industry Class 1 laser safety standards, making it an ideal solution for high-speed cloud, AI, and enterprise data center networks.

· Support 100GBASE per lane in multimode fiber

· Hot-pluggable QSFP112 Type 1 form factor

· Data rate up to 425Gbps (4x 106.25 Gbps)

· Reach up to 50m on MMF (OM4)

· 850nm VCSEL laser and PIN receiver

· High speed I/O electrical interface (400GAUI-4)

· Single MPO-12 receptacle

· Operating case temperature: 0 to +70°C

· Compliant to RoHS 6/6

· Compliant to 400G QSFP112 MSA and CMIS4.0

Absolute Maximum Ratings

Parameter	Symbol	Min.	Max.	Unit	Note
Operating Case Temperature	T_OP	0	70	°C	1,2
Power Supply Voltage	V_cc	-0.5	3.6	V
Storage Temperature Range	T_ST	-40	85	°C	1,2
Operating Relative Humidity	RH	5	85	%	1,2,3

Notes:

1. Absolute Maximum Ratings are those beyond which damage to the device may occur.

2. Between the Recommended Operating conditions and Absolute Maximum ratings, prolonged operation is not intended, and permanent device degradation may occur.

3. Non-condensing.

Optical Characteristics

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Transmitter
Signaling Rate, each Lane	-	53.125 ± 100 ppm			GBd
Modulation Format	-	PAM4			-
Center Wavelength	λ_C	842	-	948	nm
RMS Spectral Width	-	-	-	0.65	nm	1
Average Launch Power, each Lane	AOP_L	-4.6	-	4	dBm
Outer Optical Modulation Amplitude (OMAouter), each Lane	T_OMA	-	-	3.5	dBm
Outer Optical Modulation Amplitude (OMAouter), each Lane for Max(TECQ, TDECQ)≤1.8 dB for 1.8＜Max(TECQ, TDECQ)≤4.4 dB	T_OMA	-2.6 -4.4	-	-	dBm
Transmitter and Dispersion Eye Closure for PAM4 (TDECQ), each Lane	TDECQ	-	-	4.4	dB
Transmitter Eye Closure for PAM4 (TECQ), each Lane	TECQ	-	-	4.4	dB
Overshoot/Undershoot	-	-	-	29	%
Transmitter Power Excursion, each Lane	-	-	-	2.3	dBm
Extinction Ratio	ER	2.5	-	-	dB
Transmitter Transition Time, each Lane	-	-	-	17	ps
Average Launch Power of OFF Transmitter, each Lane	T_OFF	-	-	-30	dBm
RIN12OMA	RIN	-	-	-132	dB/Hz
Optical Return Loss Tolerance	ORL	-	-	14	dB
Encircled Flux	-	≥86% at 19 nm ≤30% at 4.5um			-	2
Receiver
Signaling Rate, each Lane	-	53.125 ± 100 ppm			GBd
Modulation Format	-	PAM4			-
Center Wavelength	λ_C	842	-	948	nm
Damage Threshold	AOP_D	5	-		dBm	3
Average Receive Power, each Lane	AOP_R	-6.3	-	4	dBm
Receive Power, each Lane (OMAouter)	OMA_R	-	-	3.5	dBm
Receiver Reflectance	RR	-	-	-15	dB
Receiver Sensitivity (OMAouter), each Lane for TECQ≤1.8 dB for 1.8＜TECQ≤4.4 dB	S_OMA	-	-	- -4.4 -6.2	dBm
Stressed Receiver Sensitivity (OMAouter), each Lane	SRS	-	-	-1.8	dBm	4
Conditions of Stressed Receiver Sensitivity Test						5
Stressed Eye Closure for PAM4 (SECQ)	-	-	4.4	-	dB
SECQ – 10log10(Ceq), Lane Under Test	-	-	-	4.4	dB
OMAouter of Each Aggressor Lane	-	-	3.5	-	dBm

Note:

1. RMS spectral width is the standard deviation of the spectrum.

2. If measured into type A1a.2 or type A1a.3, or A1a.4, 50 μm fiber, in accordance with IEC 61280-1-4.

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

4. Measured with conformance test signal at TP3 (see 167.8.14) for the BER specified in 167.1.1.

5. These test conditions are for measuring stressed receiver sensitivity. They are not characteristics of the receiver.

Electrical Characteristics

Parameter	Symbol	Min.	Typ.	Max.	Unit	Note
Transmitter
Signaling Rate, each Lane	-	53.125 ± 50 ppm			GBd
Differential Pk-Pk Input Voltage Tolerance	-	900	-	-	mV
Differential to Common-Mode Return Loss	RLcd	802.3ck 120G-2			dB
Effective Return Loss	ERL	8.5	-	-	dB
Differential Termination Mismatch	-	-	-	10	%
Module Stressed Input Tolerance		See 120G.3.4.3			-
Single-Ended Voltage Tolerance Range	-	-0.4	-	3.3	V
DC Common-Mode Voltage	-	-350	-	2850	mV	1
Receiver
Signaling Rate, each Lane	-	53.125 ± 50 ppm			GBd
AC Common-Mode Output Voltage	-	-	-	17.5	mV
Differential Peak-to-Peak Output Voltage Short Mode Long Mode	-	-	-	- 600 900	mV
Eye Height	EH	15	-	-	mV
Vertical Eye Closure	VEC	-	-	12	dB
Common-Mode to Differential Return Loss	RLDc	802.3ck 120G-2			dB
Effective Return Loss, ERL	ERL	8.5	-	-	dB
Differential Termination Mismatch	-	-	-	10	%
Transition Time	-	8.5	-	-	ps
DC Common-Mode Voltage1	Tr/Tf	-350	-	2850	mV	2
Power Supply						3
Power Supply Voltage	V_CC1, V_CCTx, V_CCRx	3.13	3.30	3.47	V
Power Consumption	PW	-	-	10	W
Power Consumption-LP mode	-	-	-	1.5	W

Notes:

1. DC common-mode voltage generated by the host. Specification includes effects of ground offset voltage.

2. The signaling rate range is derived from the PMD receiver input. DC common-mode voltage is generated by the host. Specification includes effects of ground offset voltage.

3. The specified characteristics are met within the recommended range of operation. Unless otherwise noted typical data are quoted at nominal voltage and +25°C ambient temperature.

Notes: