Datasheet

Data Sheet 8 Rev. 1.5, 2013-07-26
TLE7259-2GE
Functional Description
The TLE7259-2GE 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 TLE7259-2GE is selected by the EN pin. (see Figure 4).
4.2 Normal Operation Mode
The TLE7259-2GE 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 k
Ω .
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 TLE7259-2GE 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 TLE7259-2GE is disabled
and set to recessive state during the mode change procedure. To release the TLE7259-2GE for data
communication on the LIN bus, the TxD pin needs to be set to “High” for the time
t
to,rec
.
Table 1 Operating modes
Mode EN INH TxD RxD LIN Bus
Termination
Comments
Sleep Low Floating Low High
1)
High
Impedance
No wake-up request detected
Stand-By Low High Low
High
2)
Low
High
1)
1) A pull-up resistor to the external microcontroller supply is required.
30 kΩ
(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-Up
2)
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.
Normal
Operation
High High Low
High
Low
High
30 kΩ
(typical)
RxD reflects the signal on the BUS
TxD driven by the microcontroller