TLE8457ASJ datasheet(13/33 Pages) INFINEON

13 / 33 page

Data Sheet

Rev. 1.0

2016-08-05

TLE8457

LIN Transceiver with integrated Voltage Regulator

Functional Description

4.2.2

VSUndervoltage Detection

Figure 9

VS early undervoltage detection

The TLE8457 has an undervoltage detection on the supply pin VS with two different thresholds:

• In Normal Operation Mode the TLE8457 blocks the communication between the LIN bus and the

microcontroller when detecting an early undervoltage event. The RxD output will be set “high”. However,

no mode change will occur. After VS rises above the undervoltage release level VS,UV,REL, the bus

communication interface will be released when the signal on the TxD input goes “high”. See Figure 9.

• In case the power supply VS drops below the power-on reset level VS,PON the TLE8457 not only blocks the

transceiver communication, it also changes the operation mode to Init mode after recovery of VS, see

Figure 10. In Init Mode the TLE8457 indicates a power-up event on the RxD pin. The power-on reset

detection is active in all operation modes.

Figure 10

VS undervoltage detection

TLE8457_VS_EARLY_UNDERVOLTAGE_A

Power-on reset level

VS,PON

Normal Operation mode

Blanking time

tblank,UV

No communication possible

Undervoltage release level

VS,UV,ON

Undervoltage hysteresis

VS,UV,hys

Undervoltage blocking level

VS,UV,OFF

TLE8457_VS_UNDERVOLTAGE_A

Power-down

Normal Operation mode

Init mode (EN = “low“)

Normal Operation mode (EN = “high“)