TLE7258

Functional Description

Data Sheet

9

Rev. 1.1, 2015-08-20

While the TLE7258 is in Normal Operation mode the following functions are available:

•

The transmitter is turned on; data on the TxD input are driven on the LIN bus.

•

The receiver is turned on; data on the LIN bus are monitored and signaled on the RxD output.

•

The BUS pin is terminated to

V

•

The TxD input is pulled up via a current source to the internal power supply of the TLE7258.

•

The INH output is switched on.

•

The bus wake-up comparator is turned off.

•

The two-level undervoltage detection is active. In case

V

TLE7258 blocks the transmitter and receiver. In case

V

TLE7258 changes the operation mode to Standby mode after recovery (see “Undervoltage Detection” on

Page 15).

•

The EN input is active. A “low” signal on the EN input triggers a transition to Sleep.

After a mode change to Normal Operation the TLE7258 requires a logical “high” signal for the time

t

TxD input before releasing the data communication (see Figure 5). The transmitter remains deactivated as long

as the signal on the TxD input remains logical “low”, preventing possible bus communication disturbance.

4.3

Standby Mode

The Standby mode is entered automatically after:

•

A power-up event on the supply

V

•

A bus wake-up event.

•

A power-on reset caused by the supply

V

In Standby mode no communication to the LIN bus is possible. The transmitter and the receiver are disabled.

While the TLE7258 is in Standby mode the following functions are available:

•

The transmitter is turned off, the TxD input is inactive and the bus output is permanent “recessive”.

•

The receiver is turned off.

•

The RxD output indicates either a wake-up event or a power-up event (see Figure 4 and Table 1).

•

The BUS pin is terminated to

V

•

The TxD input is pulled up with a current source to the internal power supply of the TLE7258.

•

The INH output is switched on.

•

The bus wake-up comparator is active and indicates wake-up events on the RxD pin.

•

In Standby mode only the power-on reset level of the undervoltage detection is active (see “Undervoltage

Detection” on Page 15).

•

The EN input is active. A “high” signal on the EN input triggers a transition to Normal Operation mode (see

Figure 5).

After a power-up event the TLE7258 enters Standby mode by default. The EN pin has an internal pull-down

resistor and the TLE7258 remains in Standby until the external microcontroller applies a logical “high” signal at the

EN input (see Figure 6).