TLE8250G

Functional Description

Data Sheet

9

Rev. 1.0, 2010-06-02

4.3

Normal Operation Mode

In Normal Operation mode the HS CAN transceiver TLE8250G sends the serial data stream on the TxD pin to the

CAN bus while at the same time the data available on the CAN bus are monitored to the RxD pin. In Normal

Operation mode all functions of the TLE8250G are active:

•

The output driver stage is active and drives data from the TxD to the CAN bus.

•

The receiver unit is active and provides the data from the CAN bus to the RxD pin.

•

The bus basing is set to

V

•

The under-voltage monitoring on the power supply

V

To enter the Normal Operation mode set the pin NRM to logical “High” and the pin NEN to logical “Low” (see

Table 2 or Figure 4). Both pins, the NEN pin and the NRM pin have internal pull-up resistors to the power-supply

V

4.4

Receive-Only Mode

The Receive-Only mode can be used to test the connection of the bus medium. The TLE8250G can still receive

data from the bus, but the output driver stage is disabled and therefore no data can be sent to the CAN bus. All

other functions are active:

•

The output driver stage is disabled and data which are available on the TxD pin are blocked and not send to

the CAN bus.

•

The receiver unit is active and provides the data from the CAN bus to the RxD output pin.

•

The bus basing is set to

V

•

The under-voltage monitoring on the power supply

V

To enter the Receive-Only mode set the pin NRM to logical “Low” and the pin NEN to logical “Low” (see Table 2

or Figure 4). In case the Receive-Only mode will not be used, the NRM pin can be left open.

4.5

Stand-By Mode

Stand-By mode is an idle mode of the TLE8250G with optimized power consumption. In Stand-By mode the

TLE8250G can not send or receive any data. The output driver stage and the receiver unit are disabled. Both CAN

bus pins, CANH and CANL are floating.

•

The output driver stage is disabled.

•

The receiver unit is disabled.

•

The bus basing is floating.

•

The under-voltage monitoring on the power supply

V

To enter the Stand-By mode set the pin NEN to logical “High”, the logical state of the NRM pin has no influence

for the mode selection (see Table 2 or Figure 4). Both pins the NEN and the NRM pin have an internal pull-up

resistor to the power-supply

V

connected to GND.

In case the NRM pin is set to logical “Low” in Stand-By mode, the internal pull-up resistor causes an additional

quiescent current from

V

mode or leave the pin open if the Receive-Only mode is not used in the application.

4.6

Power Down Mode

Power Down mode means the TLE8250G is not supplied. In Power Down the differential input resistors of the

receiver stage are switched off. The CANH and CANL bus interface of the TLE8250G acts as an high impedance

input with a very small leakage current. The high ohmic input doesn’t influence the “Recessive” level of the CAN

network and allows an optimized EME performance of the whole CAN network.