TLE7259-3 Datasheet, PDF (8/32 Pages) Infineon Technologies AG – LIN Transceiver

TLE7259-3
Functional Description
The TLE7259-3 has 3 major operation modes:
• Stand-By mode
• Normal Operation mode
• Sleep mode
The Normal Operation mode contains 2 sub-operation modes, which differentiate by the slew rate control of the
LIN Bus signal (see Figure 4).
Sub-operation modes with different slew rates on the BUS pin:
• Normal Slope mode, for data transmission rates up to 20 kBaud
• Flash mode, for programming of the external microcontroller
The operation mode of the TLE7259-3 is selected by the EN pin. (see Figure 4).
Table 1 Operating modes
Mode
Sleep
EN INH
TxD
Low Floating Low
RxD
High¹⁾
LIN Bus Comments
Termination
High
No wake-up request detected
Impedance
Stand-By Low High
Low Low 30 kΩ
High²⁾ High ¹⁾ (typical)
RxD “Low” after local Wake-Up (pin WK) or bus wake-
up (pin BUS)
RxD “High“ after power-up
TxD strong pull down after local wake-up (WK pin)²⁾
TxD weak pull down after bus wake-up (pin BUS) or
Power-Up²⁾
Normal High High
Operation
Low Low
High High
30 kΩ
(typical)
RxD reflects the signal on the BUS
TxD driven by the microcontroller
1) A pull-up resistor to the external microcontroller supply is required.
2) The TxD input needs an external termination to indicate a “High” or a “Low” signal. The external termination could be a pull-
up resistor or an active microcontroller output.
4.2
Normal Operation Mode
The TLE7259-3 enters the Normal Operation mode after the microcontroller sets EN to “High” (see Figure 4). In
Normal Operation mode the LIN bus receiver and the LIN bus transmitter are active. Data from the microcontroller
is transmitted to the LIN bus via the TxD pin, the receiver detects the data stream on the LIN bus and forwards it to
the RxD output pin. In Normal Operation mode, the INH pin is “High” (set to V_S) and the bus termination is set to
30 kΩ.
Normal Slope mode and the Flash mode are Normal Operation modes and in these sub-modes the behavior of
the INH pin and the bus termination is the same. Per default the TLE7259-3 always enters into Normal Slope
mode, either from Sleep mode or from Stand-By mode. The Flash mode can only be entered from Normal Slope
mode.
In order to avoid any bus disturbance during a mode change, the output stage of the TLE7259-3 is disabled and
set to recessive state during the mode change procedure. To release the TLE7259-3 for data communication on
the LIN bus, the TxD pin needs to be set to “High” for the time t_to,rec.
Data Sheet
8
Rev. 1.0, 2013-08-13