The TJA1040 is able to operate in two modes determined by the STB function pin: NORMAL and STANDBY. In NORMAL mode, the transceiver is able to transmit and receive data via the bus lines. The differential receiver converts the analog data on the bus lines into digital data which is output to pin RXD via the multiplexer (MUX). The slope of the output signals on the bus lines is fixed and optimized in a way that lowers Electromagnetic Emissions (EME). In STANDBY mode, the transmitter and receiver are switched off, and the low-power differential receiver monitors the bus lines. A high level signal on the STB pin activates the low-power receiver and the wake-up filter while the state of the CAN bus is reflected on the RXD pin.