TLE7250LE

TLE7250SJ

Functional Description

Data Sheet

10

Rev. 1.0, 2015-08-12

4.2

Modes of Operation

The TLE7250 supports three different modes of operation, power-save mode, receive-only mode and normal-

operating mode while the transceiver is supplied according to the specified functional range. The mode of

operation is selected by the NEN and the NRM input pins (see Figure 4).

Figure 4

Mode state diagram

4.2.1

Normal-operating Mode

In normal-operating mode the transmitter and the receiver of the HS CAN transceiver TLE7250 are active (see

Figure 1). The HS CAN transceiver sends the serial data stream on the TxD input pin to the CAN bus. The data

on the CAN bus is displayed at the RxD pin simultaneously. A logical “low” signal on the NEN pin and a logical

“high” signal on the NRM pin selects the normal-operating mode, while the transceiver is supplied by

V

CC (see

Table 2 for details).

4.2.2

Power-save Mode

The power-save mode is an idle mode of the TLE7250 with optimized power consumption. In power-save mode

the transmitter and the normal-mode receiver are turned off. The TLE7250 can not send any data to the HS CAN

bus nor receive any data from the HS CAN bus.

The RxD output pin is permanently “high” in the power-save mode.

A logical “high” signal on the NEN pin selects the power-save mode, while the transceiver is supplied by the

transmitter supply

V

CC (see Table 2 for details).

In power-save mode the bus input pins are not biased. Therefore the CANH and CANL input pins are floating and

the HS CAN bus interface has a high resistance.

4.2.3

Receive-only Mode

In receive-only mode the normal-mode receiver is active and the transmitter is turned off. The TLE7250 can

receive data from the HS CAN bus, but cannot send any data to the HS CAN bus.

A logical “low” signal on the NEN pin and a logical “low” signal on the NRM pin selects the receive-only mode,

while the transceiver is supplied by

V

CC (see Table 2 for details).

power-save mode

NEN = 0

VCC > VCC(UV,R)

NEN = 1

NRM = “X”

normal-operating mode

NEN = 0

NRM = 1

receive-only

mode

NEN = 0

NRM = 0

VCC > VCC(UV,R)

VCC > VCC(UV,R)

NRM = 0

NEN = 0

NRM = 1

NEN = 0

NRM = 1

NEN = 1

NRM = “X”

NEN = 0

NRM = 0

NEN = 1

NRM = “X”