Data Sheet

7

Rev. 1.0

2017-08-09

HS CAN Transceiver

High Speed CAN Transceiver

High-speed CAN functional description

The TLE9250 is a high-speed CAN transceiver, operating as an interface between the CAN controller and the

physical bus medium. A HS CAN network is a two wire, differential network which allows data transmission

rates up to 5 MBit/s. The characteristic for a HS CAN network are the two signal states on the CAN bus:

“dominant” and “recessive” (see Figure 3).

The CANH and CANL pins are the interface to the CAN bus and both pins operate as an input and output. The

RxD and TxD pins are the interface to the microcontroller. The pin TxD is the serial data input from the CAN

controller, the RxD pin is the serial data output to the CAN controller. As shown in Figure 1, the HS CAN

transceiver TLE9250 includes a receiver and a transmitter unit, allowing the transceiver to send data to the bus

medium and monitor the data from the bus medium at the same time. The HS CAN transceiver TLE9250

converts the serial data stream which is available on the transmit data input TxD, into a differential output

signal on the CAN bus, provided by the CANH and CANL pins. The receiver stage of the TLE9250 monitors the

data on the CAN bus and converts them to a serial, single-ended signal on the RxD output pin. A logical “low”

signal on the TxD pin creates a “dominant” signal on the CAN bus, followed by a logical “low” signal on the RxD

pin (see Figure 3). The feature, broadcasting data to the CAN bus and listening to the data traffic on the

CAN bus simultaneously is essential to support the bit-to-bit arbitration within CAN networks.

The voltage levels for HS CAN transceivers are defined in ISO 11898-2. Whether a data bit is “dominant” or

“recessive” depends on the voltage difference between the CANH and CANL pins:

than or equal to 0.5 V.

“Partially-supplied” high-speed CAN networks are those where the CAN bus nodes of one common network

have different power supply conditions. Some nodes are connected to the common power supply, while other

nodes are disconnected from the power supply and in power-down state. Regardless of whether the CAN bus

subscriber is supplied or not, each subscriber connected to the common bus media must not interfere with

the communication. The TLE9250 is designed to support “partially-supplied” networks. In power-down state,

the receiver input resistors are switched off and the transceiver input has a high resistance.

For permanently supplied ECU's, the HS CAN transceiver TLE9250 provides a Power-save mode. In Power-save

mode, the power consumption of the TLE9250 is optimized to a minimum.

The voltage level on the digital input TxD and the digital output RxD is determined by the power supply level

RxD) are compatible with microcontrollers having a 5 V I/O supply.