1、Pin Assignment & Description

TD+, TD-:

DC coupled LVPECL inputs for the transmitter. 50Ω differential lines.

RD+, RD-:

Open-emitter out circuits. DC coupled LVPECL outputs for the receiver. 50Ω differential lines.

SD:

Signal Detect. Normal optical input levels to the receiver result in a logic “1” output, VOH, asserted. Low input optical levels to the receiver result in a fault condition indicated by a logic “0” output VOL, deasserted.

• SD is a single-ended LVPECL output and can be terminated with LVPECL techniques via 50 Ω to RX Vcc − 2V.
• Alternatively, SD can be loaded with a 180 Ω resistor to RX GND to conserve electrical power with small compromise to signal quality.
• If SD output is not used, leave it open-circuited. This SD output can be used to drive a LVPECL input on an upstream circuit, such as, SD input or Loss of Signal-bar. Connect to ground if not needed.

2、尺寸图

3、电路图

3.1、DC耦合：LVPECL互连

3.2、AC耦合

文献上的DC/AC Coupling描述可能都是错误的。

3.3、SFP和1X9 Co-lay原理图