ttsv02622 ETC-unknow, ttsv02622 Datasheet - Page 50

• Manufacturer Part Number: ttsv02622
• Description: Sts-24 Backplane Transceiver
• Manufacturer: ETC-unknow

Data Sheet
TTSV02622 STS-24 Backplane Transceiver
June 2003
LVDS I/O
®
®
The LVDS buffers are compatible with IEEE
1596.3 and EIA
/TIA-644. However, not all specs listed in the
IEEE document pertained to just the buffer itself; rather they are system-level specifications. LVDS buffers in the
TTSV02622 are compliant to all parts of the IEEE 1596.3 spec that pertain to silicon implementation.
Unused inputs will not oscillate when they are open or short-circuited. Both P and N terminals of an input pad should
not be held at voltages lower than 2.4 V. A 100
resistor is included internally, so no board termination is necessary.
Unused outputs do not need any termination, since they are terminated internally. This is valid for both powerdown
mode and functional mode.
The pin LVDS_EN is an enable that overrides any processor control over the powerdown of the LVDS input and
output pads. This is for boundary scan use only, and should be pulled high during functional mode. For boundary
scan, LVDS_EN = 0 and HIZ_N = 1.
For board layout, LVDS traces should be run on controlled impedance layers, and should be specified as 50
line-
to-ground. The LVDS buffers support point-to-point connections. They are not intended for bussed implementations.
50
Agere Systems Inc.