Product Features

The 100G QSFP28 LR4 optical transceiver integrates the transmit and receive path onto one module. On the transmit side, four lanes of serial data streams are recovered, retimed,and passed on to four laser drivers, which control four electric-absorption modulated lasers (EMLs) with 1296, 1300, 1305, and 1309 nm center wavelengths. The optical signals are then multiplexed into a single-mode fiber through an industry-standard LC connector.On the receive side, four lanes of optical data streams are optically demultiplexed by an integrated optical demultiplexer. Each data steam is recovered by a PIN photodetector and transimpedance amplifier, retimed, and passed on to an output driver. This module features a hot-pluggable electrical interface, low power consumption, and 2-wire serial interface.

Recommended Operating Conditions

Notes:

Notes:

1. Transmitter consists of 4 lasers operating at 25.78Gb/s each.
2. Minimum value is informative.
3. Hit ratio 5x10-5.
4. Receiver consists of 4 photodetectors operating at 25.78Gb/s each.
5. Minimum value is informative, equals min TxOMA with infinite ER and max channel insertion loss.
6. SRS is measured with vertical eye closure penalty of 1.8 dB max, J2 of 0.30 UI, and J9 of 0.47 UI.
7. Power value and power accuracy are with all channels on..

Pin	Name	Logic	Description
1	GND		Ground	1
2	Tx2n	CML-I	Transmitter Inverted Data Input	10
3	Tx2p	CML-I	Transmitter Non-Inverted Data Input	10
4	GND		Ground	1
5	Tx4n	CML-I	Transmitter Inverted Data Input	10
6	Tx4p	CML-I	Transmitter Non-Inverted Data Input	10
7	GND		Ground	1
8	ModSelL	LVTTL-I	Module Select	3
9	ResetL	LVTTL-I	Module Reset	4
10	Vcc Rx		+3.3V Power Supply Receiver	2
11	SCL	LVCMOS	2-wire serial interface clock	5
12	SDA	LVCMOS	2-wire serial interface data	5
13	GND		Ground	1
14	Rx3p	CML-O	Receiver Non-Inverted Data Output	9
15	Rx3n	CML-O	Receiver Inverted Data Output	9
16	GND		Ground	1
17	Rx1p	CML-O	Receiver Non-Inverted Data Output	9
18	Rx1n	CML-O	Receiver Inverted Data Output	9
19	GND		Ground	1
20	GND		Ground	1
21	Rx2n	CML-O	Receiver Inverted Data Output	9
22	Rx2p	CML-O	Receiver Non-Inverted Data Output	9
23	GND		Ground	1
24	Rx4n	CML-O	Receiver Inverted Data Output	9
25	Rx4p	CML-O	Receiver Non-Inverted Data Output	9
26	GND		Ground	1
27	ModPrsL	LVTTL-O	Module Present	6
28	IntL	LVTTL-O	Interrupt	7
29	Vcc Tx		+3.3V Power supply transmitter	2
30	Vcc1		+3.3V Power supply	2

 

31	LPMode	LVTTL-I	Low Power Mode	8
32	GND		Ground	1
33	Tx3p	CML-I	Transmitter Non-Inverted Data Input	10
34	Tx3n	CML-I	Transmitter Inverted Data Input	10
35	GND		Ground	1
36	Tx1p	CML-I	Transmitter Non-Inverted Data
37	Tx1n	CML-I	Transmitter Inverted Data Input	10
38	GND		Ground	1

Notes:

1: GND is the symbol for signal and supply (power) common for the module. All are common within the module and all module voltages are referenced to this potential unless otherwise noted. Connect these directly to the host board signal-common ground plane.

2: Vcc Rx, Vcc1 and Vcc Tx shall be applied concurrently. Vcc Rx Vcc1 and Vcc Tx may be internally connected within the module in any combination. The connector pins are each rated for a maximum current of 1000 mA. Recommended host board power supply filtering is shown below .

3: The ModSelL is an input pin. When held low by the host, the module responds to 2-wire serial communication commands. The ModSelL allows the use of multiple modules on a single 2-wire interface bus. When the ModSelL is "High", the module shall not respond to or acknowledge any
2-wire interface communication from the host. ModSelL signal input node shall be biased to the "High" state in the module. In order to avoid conflicts, the host system shall not attempt 2-wire interface communications within the ModSelL de-assert time after any modules are deselected. Similarly, the host shall wait at least for the period of the ModSelL assert time before communicating with the newly selected module. The assertion and de-asserting periods of different modules may overlap as long as the above timing requirements are met.
4: The ResetL pin shall be pulled to Vcc in the module. A low level on the ResetL pin for longer than the minimum pulse length (t_Reset_init) initiates a complete module reset, returning all user module settings to their default state. Module Reset Assert Time (t_init) starts on the rising edge after the low level on the ResetL pin is released. During the execution of a reset (t_init) the host shall disregard all status bits until the module indicates a completion of the reset interrupt. The module indicates this by asserting "low" an IntL signal with the Data_Not_Ready bit negated.
Note that on power up (including hot insertion) the module should post this completion of reset interrupt without requiring a reset.

5: Low speed signaling other than SCL and SDA is based on Low Voltage TTL (LVTTL) operating at Vcc. Vcc refers to the generic supply voltages of VccTx, VccRx, Vcc_host or Vcc1.

Hosts shall use a pull-up resistor connected to Vcc_host on each of the 2-wire interface SCL (clock), SDA (data), and all low speed status outputs. The SCL and SDA is a hot plug interface that may support a bus topology.

6: ModPrsL is pulled up to Vcc_Host on the host board and grounded in the module. The ModPrsL is asserted "Low" when inserted and deasserted "High" when the module is physically absent from the host connector.
7: IntL is an output pin. When IntL is "Low", it indicates a possible module operational fault or a status critical to the host system. The host identifies the source of the interrupt using the 2-wire serial interface. The IntL pin is an open collector output and shall be pulled to host supply voltage on the host board. The INTL pin is deasserted "High" after completion of reset, when byte 2 bit 0 (Data Not Ready) is read with a value of '0' and the flag field is read (see SFF-8636).