ocx160 ETC-unknow, ocx160 Datasheet - Page 22

• Manufacturer Part Number: ocx160
• Description: Ocx160 Crosspoint Switch
• Manufacturer: ETC-unknow

3. Differential I/O Standards
OCX160 Crosspoint Switch—Preliminary Data Sheet
3.1 LVDS
22
The OCX160 support the two most popular differential signaling standards: Low Voltage Differential Signaling
(LVDS) and Low Voltage Positive Emitter Coupled Logic (LVPECL).
LVDS is typically used in communication systems as high speed, low noise point-to-point links. The OCX160
conforms to the ANSI/TIA/EIA-644 standard covering electrical specifications for output drivers and receiver
inputs.
LVPECL is commonly used in video switching applications or those designs requiring transmission of high-
speed clock signals.
LVDS is a differential signaling standard. It requires that one data bit is carried through two signal lines.
As with all differential signaling standards, LVDS has an inherent noise immunity over single-ended
standards. The voltage swing between two signal lines is approximately 350mV. The use of a reference
voltage or a board termination voltage is not required. LVDS requires the use of two pins per input or
output. LVDS requires external resistor termination.
Transmitting and receiving circuits for LVDS are shown in Figures 7 and 8.
Device
Transmit
OCX
Data
V
LVDS Output
DD
.PAD=2.5V
from LVDS
2.5V
Driver
Figure 7
Figure 8
OUTP
OUTN
Z
Z
[Rev. 1.6] 2/20/01
0
0
=50
=50
Transmitting LVDS Signal Circuit
Receiving LVDS Signal Circuit
165
165
R
R
S
S
100
R
R
140
INN
INP
T
DIV
Z
+
–
Z
0
0
Device
=50
=50
OCX
Recieve
Data
to LVDS Receiver
to LVDS Receiver
I-Cube, Inc.