6

9146D–AUTO–09/10

Atmel ATA6663/ATA6664

3.12

Remote Wake-up via Dominant Bus State

A voltage lower than the LIN pre-wake detection V

receiver and starts the wake-up detection timer.

A falling edge at pin LIN, followed by a dominant bus level V

time period (t

switches to fail-safe mode. Pin INH is activated (switches to V

resistor is switched on. The remote wake-up request is indicated by a low level at pin RXD to

interrupt the microcontroller (see Figure 3-2).

Figure 3-2.

LIN Wake-up Waveform Diagram

In sleep mode the device has a very low current consumption, even during short-circuits or

floating conditions on the bus. A floating bus can arise if the Master pull-up resistor is missing,

e.g., in case it is switched off when the LIN Master is in sleep mode or if the power supply of

the Master node is switched off.

To minimize the current consumption I

pre-wake threshold, the receiver is activated only for a specific time t

the voltage at the bus is lower than pre-wake detection low (V

dominant level, the receiver is switched off again and the circuit reverts to sleep mode. The

current consumption is then the result of I

the bus no wake-up will occur. Even if the voltage exceeds the pre-wake detection high

(V

This means the LIN bus must be above the Pre-wake detection threshold V

microseconds before a new LIN wake-up is possible.

Microcontroller start-up

delay time

Bus wake-up filtering time

Off state

Node in sleep state

High or floating

Low or floating

Low

High

EN High

Normal

Mode

Regulator wake-up time delay

INH

External

voltage

regulator

EN

RXD

LIN bus