Datasheet

16

Rev. 1.11

2019-09-19

High Speed CAN Transceiver

TLE9251V

Changing the mode of operation

7.4

Remote wake-up

The TLE9251V has a remote wake-up feature also called bus wake-up feature according to the ISO 11898-2

(2016). In Stand-by mode the low-power receiver monitors the activity on the CAN bus and in case it detects a

wake-up pattern it indicates the wake-up signal on the RxD output pin.

The low-power receiver is supplied by the digital supply VIO and therefore in Stand-by mode the transmitter

supply VCC can be turned off.

In Stand-by mode a wake-up event on the HS CAN is flagged on the RxD output pin (see Figure 11). The

transceiver remains in the currently selected mode of operation. No mode change is applied due to the wake-

up event (see Figure 10).

Figure 10

Remote wake-up

A bus wake-up is triggered by a dedicated valid wake-up pattern. The defined wake-up pattern avoids any

false wake-up by spikes which might be on the HS CAN bus or by a permanent bus shortage.

The internal wake-up flag will be reset when:

• A mode change to Normal-operating mode is applied during the wake-up pattern.

• A power-down event occurs on the digital supply VIO.

Within the maximum wake-up time tWAKE, the wake-up pattern contents a dominant signal with the pulse

width tFilter, followed by a recessive signal with the pulse width tFilter and another dominant signal with the

pulse width tFilter (see Figure 11). The RxD output remains logical “high” as long no wake-up event has been

detected.

Stand-by

mode

STB

VCC

VIO

1

“X”

“on”

VIO “on”

STB “1”

Bus wake-up

pattern

Indication on

RxD if wake-

up pattern

detected