Datasheet

Data Sheet 17 Rev. 1.2, 2007-11-13
TLE7269G
Functional Description
In Stand-By mode the RxD1 pin signals the low power supply condition with a “High” signal. A logical “High” on
the EN pin changes the operation mode back to Normal Operation mode.
In case the supply voltage
V
S
is dropping below the specified operation range (see Table 5), the TLE7269G
disables the output and receiver stages. This feature secures the communication on the LIN bus. If the power
supply
V
S
reaches a higher level as the Under-Voltage level V
S
> V
S,UV,BLK
the TLE7269G continues with normal
operation. A mode change only applies if the power supply
V
S
drops below the power on reset level (V
S
<
V
S,UV,PON
).
If the power supply
V
IO
drops below the Under-Voltage level V
IO
> V
IO,UV
the output and receiver stages will be
disabled as well. When
V
IO
reaches a higher level as the Under-Voltage V
IO
> V
IO,UV
level the TLE7269G continues
with normal operation and data transmission.
4.11 TxD Time Out function
If the TxD1 or TxD2 signal is dominant for a time t > t
timeout
the TxD time-out function deactivates the transmission
of the LIN signal to the bus and disables both, the output stage 1 and the output stage 2. This is realized to prevent
the bus from being blocked by a permanent “Low” signal on the TxD1 or TxD2 pin, caused by an error on the
external microcontroller (see Figure 12).
The transmission is released again, after a rising edge at TxD1 or TxD2 has been detected.
Figure 12 TxD Time-Out function
TxD1
t
torec
BUS1
TxD2
BUS2
t
timeout
Normal Communication
Normal Communication
TxD Time-Out due to
microcontroller error
Release after TxD
Time-out
Recovery of the
microcontroller error
t
torec
t
timeout
Normal Communication
Normal Communication
TxD Time-Out due to
microcontroller error
Release after TxD
Time-out
Recovery of the
microcontroller error
t
t
t
t