Data Sheet

18

Rev. 1.0

2016-08-05

TLE8457

LIN Transceiver with integrated Voltage Regulator

Functional Description

4.5.1

TxD Time-out

The TxD time-out feature protects the LIN bus against permanent blocking in case the logical signal on the TxD

input is continuously “low”, caused by for example a malfunctioning microcontroller or a short circuit on the

disables the transmitter’s output driver stage (see Figure 15). The receiver will remain active and the data on

the bus are still monitored on the RxD output.

The TLE8457 will release the output stage after a TxD time-out event first when detecting a logical “high”

Figure 15

TxD time-out

4.5.2

Short Circuit

over-temperature protection may disable the transmitter if a permanent short circuit on the BUS pin causes

the TLE8457 to overheat.

4.6

Over-temperature Protection

The TLE8457 has two independent over-temperature detectors for protecting the device against thermal

overstress; on the voltage regulator pass element and on the LIN bus transmitter. In case the junction

occur. After a LIN transmitter over-temperature recovery the TxD input requires a logical “high” signal before

restarting data transmission.

If an over-temperature event is detected on the voltage regulator, it will be disabled and the NRST output will

be set “low”. During the over-temperature condition no functionality of the TLE8457 is available. After the

reactivated.

Note:

Depending on the over-temperature circumstance, either only the LIN transmitter will detect over-

temperature, for example due to bus short circuit or severe EMC injection, only the voltage regulator

detector or both (simultaneously or sequentially).

TLE8457_TXD_TIMEOUT_A

t

TxD

TxD time-out due to e.g. microcontroller error

Release after TxD time-out

Recovery of the microcontroller error

t

Normal communication

Normal communication