Driver Output Protection

Thermal Shutdown

If the junction temperature exceeds +165°C, the driver is

switched off. Thermal hysteresis is 15°C, disabling ther-

mal shutdown once the temperature reaches +150°C.

Overcurrent Protection

A current-limiting circuit protects the transmitter output

stage against a short circuit to a positive and negative

battery voltage. Although the power dissipation increases

during this fault condition, this feature prevents destruc-

tion of the transmitter output stage.

Failure Management

The failure detector is fully active in normal operating

mode. After the detection of a single failure, the detec-

tor switches to the appropriate state (see Table 1).

The differential receiver threshold voltage is set to -3.2V

with a noise margin as high as possible in the normal

operating mode and in the event of failures 1, 2, 5, and 9.

If any of the wiring failures occur, the output signal on

pin ERR becomes LOW after detection. On error recov-

ery, the output signal on pin ERR becomes HIGH.

±80V Fault-Protected/Tolerant CAN

Transceivers for In-Car Applications

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13

FAILURE

DESCRIPTION

MODE

1

CANH wire interrupted

Normal

2

CANL wire interrupted

Normal

3

CANH short circuited to battery

All

4

CANL short circuited to ground

All

5

CANH short circuited to ground

Normal

6

CANL short circuited to battery

Normal

7

CANL mutually short circuited to CANH

All

8

All

9

Normal

Table 1. Failure States

MODE

DESCRIPTION

Detection

The external termination resistance connected to the RTH pin provides an instantaneous pulldown of the open

CANH line to GND. Detection is provided, sensing the pulse-count difference between CANH and CANL (pulse

count = 4).

Receiver

The receiver remains in differential mode. No received data lost.

Driver

Driver remains in differential mode. No transmission data lost.

Recovery

Recovery is provided sensing the pulse-count difference between CANH and CANL after the detection of four

consecutive pulses.

Failure 1—CANH Wire Interrupted (Normal Mode Only)

MODE

DESCRIPTION

Detection

The external termination resistance connected to the RTL pin provides an instantaneous pullup of the CANL line to

Receiver

The receiver remains in differential mode. No received data lost.

Driver

Driver remains in differential mode. No transmission data lost.

Recovery

Recovery is provided, sensing the pulse-count difference between CANL and CANH after the detection of four

consecutive pulses.

Failure 2—CANL Wire Interrupted (Normal Mode Only)