TXN31115D200000 Intel, TXN31115D200000 Datasheet - Page 14

• Manufacturer Part Number: TXN31115D200000
• Description: TXRX OPT SFP 150M 850NM MULTI
• Manufacturer: Intel

Specifications of TXN31115D200000

• Data Rate: 4.25Gbps
• Wavelength: 850nm
• Applications: Ethernet
• Connector Type: LC Duplex
• Mounting Type: SFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Other names: 874223

4.0
4.1
4.2
Figure 2.
Intel
Datasheet
14
®
TXN31115D2 Quad-Rate 850 nm Optical Transceiver - SFP MSA Compatible
Termination
Types of I/O Interfaces
The TXN31115D2 Optical Transceiver has the following types of I/O interfaces.
High-speed I/Os use the CML interface, while control signals use the TTL interface.
Proper termination of I/Os is required for good signal integrity. If I/Os (particularly the
CML I/Os) are not terminated properly, then jitter increases significantly due to
reflection from impedance mismatches.
CML Termination
Figure 2
Transceiver receiver output. The TXN31115D2 Optical Transceiver has built in AC-
coupling capacitors, which help prevent a direct current path from the TXN31115D2
Optical Transceiver power supply to the SerDes input. (A direct current path could
damage the ESD diodes on the SerDes.)
Circuit Diagram for CML Termination on Receiver Output
• CML interface
• TTL interface
• Internal termination. For the TXN31115D2 Optical Transceiver receiver output,
• External termination. For the proper external termination of the SerDes
3.3 V
the SerDes interface provides an internal termination resistor.
interface, refer to the SerDes specification.
shows a circuit diagram for the CML termination for the TXN31115D2 Optical
50 Ω
Receiver Output
AC-coupling
capacitor
Document Number:311473, Revision: 006US
TXN31115D2 Optical Transceiver
100 Ω
SerDes Input
B3243-02
26-Sep-2007