High-Speed Differential Interfaces in Cyclone II Devices
Table 11–1. LVDS I/O Specifications (Part 2 of 2)
Note (1)
Symbol
Parameter
Condition
Min
Typ
Max
Units
VID
Input differential voltage
(single-ended)
0.1
0.65
V
VICM
ΔVOS
RL
Input common mode
voltage
0.1
90
2.0
50
V
mV
Ω
Change in VOS between RL = 100 Ω
H and L
Receiver differential input
resistor
100
110
Note to Table 11–1:
(1) The specifications apply at the resistor network output.
LVDS Receiver & Transmitter
Figure 11–3 shows a simple point-to-point LVDS application where the
source of the data is an LVDS transmitter. These LVDS signals are
typically transmitted over a pair of printed circuit board (PCB) traces, but
a combination of a PCB trace, connectors, and cables is a common
application setup.
Figure 11–3. Typical LVDS Application
Cyclone II Device
Transmitting Device
Receiving Device
txout +
rxin +
txout +
txout -
rxin +
Cyclone II
Logic
Array
120 Ω
120 Ω
100 Ω
170 Ω
rxin -
100 Ω
rxin -
txout -
Input Buffer
Output Buffer
Figures 11–4 and 11–5 show the signaling levels for LVDS receiver inputs
and transmitter outputs, respectively.
Altera Corporation
February 2007
11–5
Cyclone II Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
