ATA6664 Ver la hoja de datos (PDF) - Atmel Corporation

Número de pieza

componentes Descripción

Fabricante

ATA6664

LIN Transceiver

Atmel Corporation 

3.12

Remote Wake-up via Dominant Bus State

A voltage lower than the LIN pre-wake detection VLINL at pin LIN activates the internal LIN

receiver and starts the wake-up detection timer.

A falling edge at pin LIN, followed by a dominant bus level VBUSdom maintained for a certain

time period (tBUS) and a rising edge at pin LIN results in a remote wake-up request. The device

switches to fail-safe mode. Pin INH is activated (switches to VS) and the internal termination

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 bus

LIN Wake-up Waveform Diagram

Bus wake-up filtering time

(tBUS)

INH

RXD

External

voltage

regulator

EN

Low or floating

High or floating

Off state

Node in sleep state

High

Low

Regulator wake-up time delay

Normal

Mode

EN High

Microcontroller start-up

delay time

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 IVS during voltage levels at the LIN-pin below the LIN

pre-wake threshold, the receiver is activated only for a specific time tmon. If tmon elapses while

the voltage at the bus is lower than pre-wake detection low (VLINL) and higher than the LIN

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

current consumption is then the result of IVSsleep plus ILINwake. If a dominant state is reached on

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

(VLINH), the IC will remain in sleep mode (see Figure 3-3 on page 7).

This means the LIN bus must be above the Pre-wake detection threshold VLINH for a few

microseconds before a new LIN wake-up is possible.

6 Atmel ATA6663/ATA6664

9146D–AUTO–09/10

Share Link: