TLE7257 Datasheet, PDF (26/31 Pages) Infineon Technologies AG – LIN Transceiver

TLE7257
Application Information
Table 9 TxD Termination
Operation Mode
Normal Operation mode
Standby mode
Sleep mode
Remarks
The internal pull-up structure is active, in case the TxD input is open the
TxD input signal is “high” and the output on the BUS pin is “recessive”
The internal pull-up structure is active, in case the TxD input is open the
TxD input signal is “high”. In Standby mode the transmitter is turned off
and therefore the output on the BUS pin always is “recessive”
The internal pull-up structure is inactive, in case the TxD input is open the
TxD input signal is “floating”. In Sleep mode the transmitter is turned off
and therefore the output on the BUS pin always is “recessive”
7.6
RxD Pull-up Resistor
The receive data output (RxD) provides an open drain behavior for allowing the output level to be adapted to the
microcontroller supply voltage. Thus 3.3 V microcontroller derivatives without 5 V tolerant ports can be used. In
case the microcontroller port pin does not provide an integrated pull-up, an external pull-up resistor connected to
the microcontroller’s V_CC supply voltage is required.
The typical RxD pin current / voltage characteristic over temperature is given in Figure 17. With the applications
microcontroller port pins’ (Rx) minimum “high”-level and maximum “low”-level input voltage the pull-up resistor can
be dimensioned. For most applications a pull-up resistor R_Rx of 2.4 kΩ is recommended.
1.4
T_j = −40°C
1.2
T_j = 27°C
T_j = 150°C
1
0.8
0.6
0.4
0.2
0
0
1
2
3
4
5
6
7
8
I_RxD [mA]
Figure 17 Typical RxD output sink characteristics
Data Sheet
26
Rev. 1.0, 2013-10-16