Datasheet

Data Sheet 20 Rev. 1.1, 2011-06-06
TLE6251-3G
Fail Safe Features
7.2.5 Over-Temperature Detection
The output driver stage is protected against over temperature. Exceeding the shutdown temperature results in
deactivation of the output driving stage. To avoid any toggling after the device cools down, the output driver stage
is enabled again only after a “Recessive” to “Dominant” signal change on the TxD pin (see Figure 11).
An Over-Temperature event only deactivates the output driver stage, the TLE6251-3G doesn’t change its
operation mode in this failure case. The Over - Temperature event is indicated by a logical “Low” signal on the
NERR pin in Receive-Only mode.
Figure 11 Release of the Transmission after an Over-Temperature event
7.3 Under-Voltage Detection
The TLE6251-3G provides a power supply monitoring on all three power supply pins: V
CC
, V
IO
and V
S
. In case of
an under - voltage event on any of this three power supplies, the TLE6251-3G changes the operation mode and
sets an internal failure flag. The internal failure flag is not indicated by the NERR output pin.
7.3.1 Under-Voltage Event on V
CC
and V
IO
An under-voltage event on the power supply V
CC
or the power supply V
IO
causes the change of the operation mode
to Sleep mode, regardless of the operation mode in which the TLE6251-3G might currently operate. The logical
signals on the digital input pins EN and NSTB are also disregarded. After the power supplies
V
CC
and V
IO
are
activated again, the operation mode can be changed the usual way. From Sleep mode to Stand-By mode by a
Wake-Up event or from Sleep mode direct to Normal Operation mode, Receive-Only mode by the digital input pins
EN and NSTB.
TxD
t
CANH
CANL
RxD
Normal Operation mode
t
t
t
Temp.
Output-Stage Release
Thermal Shutdown
Temp. T
JSD
Thermal Shutdown
Hysteresis ΔT
J
Cool Down