TLE8457BLE datasheet(12/33 Pages) INFINEON

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Data Sheet

Rev. 1.0

2016-08-05

TLE8457

LIN Transceiver with integrated Voltage Regulator

Functional Description

4.2

Power Supplies

The TLE8457 is designed for being supplied by the battery line through an external reverse polarity protection

diode at the VS pin (see Figure 18). An input capacitor is needed for damping input line transients.

4.2.1

Power-Up / Power-Down

During power-up the TLE8457 will enter Init Mode when the VS supply reaches the power-on reset level VS,PON.

The voltage regulator output VCC will track the VS supply voltage until VCC reaches its nominal voltage level. As

VCC reaches the under-voltage level VCC,UVC, a reset pulse is issued, the NRST output will stay logical “low” for

the reset time tRST and then be set logical “high”. As NRST goes “high”, the EN input will become active and the

TLE8457 can change operating mode accordingly (see Table 2).

Figure 8

Power-up and power-down behavior

While powering down the TLE8457 will block the LIN transmitter if being in Normal Operation Mode as the VS

supply voltage falls below VS,UV,OFF. The voltage regulator will start tracking the VS supply voltage when falling

below VCC + VDR. As VCC falls below the undervoltage level VCC,UV the NRST output will be set logical “low” and

the TLE8457 will enter Init Mode. When the VS supply voltage falls below the power-on-reset level VS,PON the

voltage regulator will be disabled and the TLE8457 considered un-powered.

TLE8457_VS_POWER-UP_DOWN

un-powered

VS,PON

VCC

Init mode

Normal Operation mode

VCC,UV

Init mode

un-powered

VS,UV,OFF

VS,PON

Transmission blocked

NRST

tRST

VS,UV,ON

VCC,UV

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