Datasheet

TLE6251-3G
Wake-Up Functions
Data Sheet 15 Rev. 1.1, 2011-06-06
6.2 Local Wake-Up
The TLE6251-3G can be activated from Sleep mode by a signal change on the WK pin, also called local Wake-
Up. Designed to withstand voltages up to 40V the WK pin can be directly connected to
V
S
. The internal logic on
the WK pin works bi-sensitive, meaning the Wake-Up logic on the pin WK triggers on a both signal changes, from
“High” to “Low” and from “Low” to “High” (see Figure 7).
Figure 7 Local Wake - Up
A filter time
t
WK(local)
is implemented to protect the TLE6251-3G against unintended Wake-Up’s, caused by spikes
on the pin WK. The threshold values
V
WK,H
and V
WK,L
depend on the level of the V
S
power supply.
In Stand-By mode the RxD output pin and the NERR output pin display the CAN bus Wake-Up event by a logical
“Low” signal (Details see Chapter 8). Once the HS CAN Transceiver TLE6251-3G has recognized the Wake-Up
event and has changed to Stand-By mode, the INH output pin becomes active and provides the voltage
V
S
to the
external circuitry.
V
WK
INH
t > t
Wk(local)
Stand-By mode
t
t
Sleep mode
Wake-Up
t < t
Wk(local)
No Wake-Up
V
WK
INH
t > t
Wk(local)
Stand-By Mode
t
t
Sleep Mode
Wake-Up
t < t
Wk(local)
No Wake-Up
Stand-By modeSleep mode
V
WK,H
V
WK,L