L9952XP datasheet(22/68 Pages) STMICROELECTRONICS

22 / 68 page

Description

L9952GXP

22/68

Doc ID 13518 Rev 5

2.17

Error handling

The L9952GXP provides the following 3 error handling features which are not described in

the LIN Spec. V2.1, but are realized in different stand alone LIN transceivers / micro

controllers to switch the application back to normal operation mode.

2.17.1

Dominant TxD time out

If TXI is in dominant state (low) for more than 12ms (typ) the transmitter will be disabled until

TXI becomes recessive (high). This feature can be disabled via SPI.

2.17.2

Short to battery time out

If TXI changes to dominant (low) state but RXI signal does not follow within 40

µs, the

transmitter will be disabled until TXI becomes recessive (high).

2.17.3

Short to ground mode

A wake up caused by a message on the bus will start the voltage regulator and the micro

controller to switch the application back to normal operation mode.

2.18

Wake up (from LIN)

In standby mode the L9952GXP can receive a wake up from LIN bus. For the wake up

feature the L9952GXP logic differentiates two different conditions.

2.18.1

Normal wake up

Normal wake up can occur when the LIN transceiver was set in standby mode while LIN was

in recessive (high) state. A dominant level at LIN for at least 40µs, will switch the L9952GXP

to active mode.

2.18.2

Wake up from short to GND condition

If the LIN transceiver was set in standby mode while LIN was in dominant (low) state,

recessive level at LIN for at least 40us, will switch the L9952GXP to active mode.

2.18.3

RxD pin in V1 standby

In V1 standby condition the RxD is a tristate pin.

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