Data Sheet

9

Rev. 1.0

2016-08-05

TLE8457

LIN Transceiver with integrated Voltage Regulator

Functional Description

4.1.3

Init Mode

After a power-up event the TLE8457 enters Init Mode by default. In this mode the LIN transceiver is disabled,

but the voltage regulator is switched on. Following the linear voltage regulator has reached its nominal output

Operation Mode. If the Initialization Watchdog timer elapses before a “high” signal is detected on the EN input,

the TLE8457 will autonomously transition to Sleep Mode (see “Initialization Watchdog” on Page 15). The

Initialization Watchdog protection in Init Mode is always activated after starting up the voltage regulator and

after a reset pulse, triggered by the NRST output going “high”.

In Init Mode the TLE8457 indicates wake-up information on the RxD output. After a power-up and reset event,

the RxD output will be “high”. If the TLE8457 is in Init Mode after BUS wake-up detection, the RxD output will

be “low”.

Transitions to Init Mode can be controlled with the EN input when in Sleep Mode, or automatic forced after:

• Bus wake-up event on the BUS pin.

• Recovery of an over-temperature event on the voltage regulator.

Figure 5

Entering Init Mode after power-up

TLE8457_INIT_MODE

Init mode

Un-powered

The device remains in Init mode while the

signal on the EN pin is „low“

EN

LIN

Normal Operation mode

RxD signals Power-up

RxD signals Bus Wake-up

NRST

t

RxD

t

t

t

t

t