Data Sheet

ADN4691E/ADN4693E/ADN4696E/ADN4697E

Rev. A | Page 15 of 20

GLITCH-FREE POWER-UP/POWER-DOWN

To minimize disruption to the bus when adding nodes, the

M-LVDS outputs of the device are kept glitch-free when the

device is powering up or down. This feature allows insertion of

devices onto a live M-LVDS bus because the bus outputs are not

switched on before the device is fully powered. In addition, all

outputs are placed in a high impedance state when the device is

powered off.

FAULT CONDITIONS

The ADN4691E/ADN4693E/ADN4696E/ADN4697E contain

short-circuit current protection that protects the part under

fault conditions in the case of short circuits on the bus. This

protection limits the current in a fault condition to 24 mA at

the transmitter outputs for short-circuit faults between −1 V

and +3.4 V. Any network fault must be cleared to avoid data

transmission errors and to ensure reliable operation of the data

network and any devices that are connected to the network.

RECEIVER INPUT THRESHOLDS/FAIL-SAFE

Two receiver types are available, both of which incorporate

protection against short circuits.

The Type 1 receivers of the ADN4691E/ADN4693E incorporate

25 mV of hysteresis. This ensures that slow-changing signals or

a loss of input does not result in oscillation of the receiver output.

Type 1 receiver thresholds are ±50 mV; therefore, the state of the

receiver output is indeterminate if the differential between A and

B is about 0 V. This state occurs if the bus is idle (approximately 0 V

on both A and B), with no drivers enabled on the attached nodes.

Type 2 receivers (ADN4696E/ADN4697E) have an open circuit

and bus-idle fail-safe. The input threshold is offset by 100 mV so

that a logic low is present on the receiver output when the bus is

idle or when the receiver inputs are open.

The different receiver thresholds for the two receiver types are

illustrated in Figure 36. See Table 12 and Table 13 for receiver

output states under various conditions.

TYPE 1 RECEIVER

OUTPUT

LOGIC 1

LOGIC 0

0.25

0.15

0.05

–0.05

–0.15

0

TYPE 2 RECEIVER

OUTPUT

LOGIC 1

LOGIC 0

UNDEFINED

UNDEFINED

Figure 36. Input Threshold Voltages