
ADN4691E/ADN4693E/ADN4696E/ADN4697E
Data Sheet
Rev. A | Page 14 of 20
THEORY OF OPERATION
transceivers for transmitting and receiving multipoint, low
voltage differential signaling (M-LVDS) at high speed (data
rates up to 200 Mbps). Each device has a differential line driver
and a differential line receiver, allowing each device to send and
receive data.
Multipoint LVDS expands on the established LVDS low voltage
differential signaling method by allowing bidirectional commu-
nication between more than two nodes. Up to 32 nodes can be
connected on an M-LVDS bus.
HALF-DUPLEX/FULL-DUPLEX OPERATION
Half-duplex operation allows a transceiver to transmit or
receive, but not both at the same time. However, with full-
duplex operation, a transceiver can transmit and receive
devices in which the driver and the receiver share differential
devices that have dedicated driver output and receiver input
bus topologies, respectively, for M-LVDS.
THREE-STATE BUS CONNECTION
The outputs of the device can be placed in a high impedance
state by disabling the driver or receiver. This allows several
driver outputs to be connected to a single M-LVDS bus. Note
that, on each bus line, only one driver can be enabled at a time,
but many receivers can be enabled at the same time.
The driver can be enabled or disabled using the driver enable
pin (DE). DE enables the driver outputs when taken high; when
taken low, DE puts the driver outputs into a high impedance state.
Similarly, an active low receiver enable pin (RE) controls the
receiver. Taking RE low enables the receiver, whereas taking it
high puts the receiver outputs into a high impedance state.
Truth tables for driver and receiver output states under various
TRUTH TABLES
Table 9. Truth Table Abbreviations
Abbreviation
Description
H
High level
L
Low level
X
Don’t care
I
Indeterminate
Z
High impedance (off )
NC
Disconnected
Table 10. Transmitting (See Table 9 for Abbreviations) Inputs
Outputs
Power
DE
DI
A
B
Yes
H
L
Yes
H
L
H
Yes
H
NC
L
H
Yes
L
X
Z
Yes
NC
X
Z
≤1.5 V
X
Z
Table 11. Transmitting (See Table 9 for Abbreviations) Inputs
Outputs
Power
DE
DI
Y
Z
Yes
H
L
Yes
H
L
H
Yes
H
NC
L
H
Yes
L
X
Z
Yes
NC
X
Z
≤1.5 V
X
Z
Table 12. Receiving (see Table 9 for Abbreviations) Inputs
Output
Power
A B
RE
RO
Yes
≥50 mV
L
H
Yes
≤50 mV
L
Yes
50 mV < A B < 50 mV
L
I
Yes
NC
L
I
Yes
X
H
Z
Yes
X
NC
Z
No
X
Z
Table 13. Receiving (See Table 9 for Abbreviations) Inputs
Output
Power
A B
RE
RO
Yes
≥150 mV
L
H
Yes
≤50 mV
L
Yes
50 mV < A B < 150 mV
L
I
Yes
NC
L
Yes
X
H
Z
Yes
X
NC
Z
No
X
Z