Datasheet

15

Rev. 1.20

2022-04-27

TLE7258

LIN transceiver

Functional description

3.8

Undervoltage detection

Figure 11 Early undervoltage detection

The TLE7258 has undervoltage detection on the VS supply pin with two different thresholds:

• In normal operation mode the TLE7258 blocks the communication between the LIN bus and the

microcontroller when detecting undervoltage events. 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 11.

• In case the power supply VS drops down below the power-on reset level VS,UV,PON the TLE7258 not only

blocks the communication between the LIN bus and the microcontroller, it also changes the operation

mode to standby mode after VS supply recovery. In standby mode the TLE7258 indicates a power-up event

on the RxD output. The power-on reset level is active in all operation modes.See Figure 12.

Figure 12 Undervoltage detection and power-on reset

TLE7258_UNDERVOLTAGE_EARLY

Supply voltage

V

S

Power-on reset level

V

S,UV,PON

Normal Operation mode

Normal Operation mode

Blanking time

t

blank,UV

Communication blocked

Undervoltage release level

V

S,UV,ON

Undervoltage hysteresis

V

S,UV,HYS

V

S

t

Undervoltage

detection level

V

S,UV,OFF

TLE7258_UNDERVOLTAGE_RESET

Device unpowered

Supply voltage

V

S

Normal Operation mode

Standby mode (EN = „low“)

Normal Operation mode (EN = “high“)

Blanking time

t

blank,UV

Undervoltage release level

V

S,UV,ON

Undervoltage hysteresis

V

S,UV,HYS

Power-on reset level

V

S,UV,PON

Communication blocked

V

S

t

Undervoltage

detection level

V

S,UV,OFF