TLE7257 Datasheet, PDF (8/31 Pages) Infineon Technologies AG – LIN Transceiver

TLE7257
Functional Description
Table 2
Number
1
2
3
4
5
Operation mode transitions
Reason for transition
Comment
Power-on detection
The V_S supply voltage rise above the V_S,UV,PON power-on reset level
Mode change with EN input Triggered by logical “high” level
Mode change with EN input Triggered by logical “low” level
Mode change with EN input Triggered by logical “high” level
Bus wake-up detection
RxD set “low” for signalling the bus wake-up event to the microcontroller
4.2
Normal Operation Mode
While operating in Normal Operation mode the LIN bus receiver and transmitter are active and support data
transmission rates up to 20 kbps. Data from the microcontroller is transmitted to the LIN bus via the TxD input.
Simultaneously the receiver detects the data stream on the LIN bus and forwards it to the RxD output.
Normal Operation mode can be entered from either Sleep mode (see Figure 9) or from Standby mode (see
Figure 5), by setting the EN input to logical “high”. From Normal Operation mode the TLE7257 can only enter
Sleep mode, it is not possible to enter Standby mode directly (see Figure 4).
The transition time for mode change to Normal Operation mode t_MODE specifies the delay between the threshold,
where the EN pin detects a “high” input signal, and the actual mode change of TLE7257 to Normal Operation
mode.
V_EN,ON
EN
t_MODE
RxD
RxD: „high“ or „low“
t_to,rec
TxD
TxD: „high“ because
of internal pull-up
V_EN,OFF
Data transmission
Data transmission
Hysteresis
t
t_MODE
t
TxD: „high impedance“
t
INH
INH: „high impedance“
Standby mode
Normal Operation mode
t
Sleep mode
Standby mode:
Sleep mode:
The internal pull-up current source sets the TxD input to logical „high“ in case the TxD input is open.
The internal pull-up current source is switched off and the TxD input is disabled. The TxD input is floating
in case the TxD input is open.
TLE7257_NORMAL_MODE
Figure 5 Entering Normal Operation mode from Standby mode
Data Sheet
8
Rev. 1.0, 2013-10-16