TLE7251V_15 Datasheet, PDF (10/36 Pages) Infineon Technologies AG – High Speed CAN-Transceiver with Bus Wake-up

TLE7251VLE
TLE7251VSJ
Functional Description
4.2
Modes of Operation
The TLE7251V supports two different modes of operation, stand-by mode and normal-operating mode while the
transceiver is supplied according to the specified functional range. The mode of operation is selected by the STB
input pin (see Figure 4).
V_CC = “don’t care”
V_IO > V_IO(UV,R)
stand-by mode
STB = 1
STB = 0
STB = 1
V_CC > V_CC(UV,R)
V_IO > V_IO(UV,R)
normal-operating
mode
STB = 0
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 TLE7251V 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 STB pin selects the
normal-operating mode, while the transceiver is supplied by V_CC and V_IO (see Table 2 for details).
4.2.2 Stand-by Mode
The stand-by mode is an idle mode of the TLE7251V with optimized power consumption. In stand-by mode the
transmitter and the normal-mode receiver are turned off. The TLE7251V can not send any data to the CAN bus
nor receive any data from the CAN bus.
The low-power receiver is connected to the bus lines. Wake-up signals are indicated on the RxD output pin. An
additional filter, implemented inside the low-power receiver, ensures that only “dominant” and recessive” signals
on the CAN bus, which are longer than the CAN activity filter time t_Filter, are indicated at the RxD output pin (see
Figure 8).
A logical “high” signal on the STB pin selects the stand-by mode, while the transceiver is supplied by the digital
supply V_IO (see Table 2 for details).
In stand-by mode the bus input pins are biased to GND via the receiver input resistors R_i.
The undervoltage detection on the transmitter supply V_CC is turned off, allowing to switch off the V_CC supply in
stand-by mode.
Data Sheet
10
Rev. 1.0, 2015-09-10