TLE8458

LIN Transceiver

Data Sheet

21

Rev. 1.1, 2014-04-01

7.1.1

Undervoltage Detection

A dropping power supply

V

S on a local ECU can effect the communication of the whole LIN network. To avoid any

blocking of the LIN network by a local ECU the TLE8458 has an integrated Power-On reset at the supply

V

S and

an undervoltage detection at the supply

V

S. In case the supply voltage VS is dropping below the Power-On reset

level

V

S < VS,UV,PON, the TLE8458 changes the operation mode to Stand-By mode. In Stand-By mode the output

stage of the TLE8458 is disabled and no communication to the LIN bus is possible. The internal bus termination

remains active as well as the

V

CC output voltage. (see Figure 1 and Figure 11).

In Stand-By mode the RxD pin indicates the low power supply condition with a logical HIGH signal. Setting the EN

pin to logical HIGH changes the operation mode back to Normal Operation mode.

In case the supply voltage

V

S is dropping below the undervoltage reset level VS < VSUV (see Figure 11), the

TLE8458 disables the output and receiver stages. This feature secures the communication on the LIN bus. If the

power supply

V

S reaches a higher level as the undervoltage reset level VS > VSUV the TLE8458 continues with

normal operation. A mode change only applies if the power supply

V

S drops below the power on reset level

(

V

S < VS,UV,PON).

Figure 11

Under-Voltage Detection

Supply voltage Vs

Power on reset level

VS,UV,PON

Power On reset

Normal Operation

Mode

Reset and

Communication

blocked

Stand-By

Mode

Blanking time

tUV

Supply voltage Vs

Power on reset level

VS,UV,PON

Normal Operation

Mode

Communication

blocked

Blanking time

tUV

Under Voltage level

VSUV

Normal Operation

Mode

Under Voltage

Detection VS