ICS8M 4
X
Integrated
Circuit
Systems, Inc.
Crystal Oscillator: LVPECL CLOCK
O
UTPUT
PRELIMINARY
PARAMETER MEASUREMENT INFORMATION (CONTINUED)
VDD
VDD
➤
out
out
IOSD
DC Input
LVDS
LVDS
DC Input
100
V
OD/∆ VOD
➤
out
out
Differential Output Short Circuit Current Setup
Differential Output Voltage Setup
VDD
V
VDDDD
out
IOS
out
➤
DC Input
LVDS
DC Input
LVDS
IOSB
out
out
VOS/∆ VOS
➤
Output Short Circuit Current Setup
Offset Voltage Setup
LVDS
VDD
VDD
IOFF
Power Off Leakage Setup
APPLICATION INFORMATION
TERMINATION FOR 3.3V LVDS DRIVER
TERMINATION FOR 2.5V LVDS DRIVER
A general LVDS interface is shown in Figure 1. In a 100W differential transmis-
sion line environment, LVDS drivers require a matched load termination of 100W
across near the receiver input. For a multiple LVDS outputs buffer, if only partial
outputs are used, it is recommended to terminate the un-used outputs.
Figure 2 shows a typical termination for LVDS driver in characteristic impedance
of 100Ωdifferential (50Ωsingle) transmission line environment. For buffer with
multiple LDVS driver, it is recommended to terminate the unused outputs.
3.3V
3.3V
3.3V
2.5V
3.3V
3.3V
3.3V
2.5V
LVDS Driver
LVDS
LVDS Driver
LVDS
+
-
+
-
R1
R1
100
100
100Ω Differential Transmission Line
100 Ohm Differential Transmission Line
100Ω Differential Transmission Line
100 Ohm Differential Transmission Line
Figure 1: Typical 3.3V LVDS Driver Termination
Figure 2: Typical 3.3V LVDS Driver Termination
ICS8Mx4 Datasheet Rev A
3 of 4
Revised 30Nov2004
Integrated Circuit Systems, Inc. ● Networking & Communications ● www.icst.com ● tel (508) 852-5400