L99PM72GXP datasheet(33/129 Pages) STMICROELECTRONICS

33 / 129 page

DocID024767 Rev 4

33/129

L99PM72GXP

Detailed description

128

Permanent dominant

If the bus state is dominant (low) for more than 12 ms a permanent dominant status is

detected. The status bit is latched and can be read and optionally cleared by SPI. The

transmitter is not disabled.

2.8.2

Wake up (from LIN)

In standby mode the L99PM72GXP can receive a wake up from LIN bus. For the wake up

feature the L99PM72GXP logic differentiates two different conditions.

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 tlinbus, switches the L99PM72GXP

to active mode.

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 tlinbus, switchs the L99PM72GXP to active mode.

Note:

A wake up caused by a message on the bus starts the voltage regulator and the

microcontroller to switch the application back to normal operation mode.

2.8.3

LIN Pull-Up

The master node pull-up resistor (1 k

Ω) can be connected to VS using the internal LIN_PU

high side switch. This high side switch can be controlled by SPI in order to allow

disconnection of the pull-up resistor in case of LIN bus short to GND conditions.

Figure 18. Master node configuration using LIN_PU (optional)

L99PM72GXP 数据表(PDF) 33 Page - STMicroelectronics