SLLSFG2 December 2019 – December 2019 TCAN1044V
PRODUCTION DATA.
The CAN bus has two logical states during operation: recessive and dominant. See Figure 12 and Figure 13.
A dominant bus state occurs when the bus is driven differentially and corresponds to a logic low on the TXD and RXD pins. A recessive bus state occurs when the bus is biased to VCC/2 via the high-resistance internal input resistors (RIN) of the receiver and corresponds to a logic high on the TXD and RXD pins.
A dominant state overwrites the recessive state during arbitration. Multiple CAN nodes may be transmitting a dominant bit at the same time during arbitration, and in this case the differential voltage of the bus is greater than the differential voltage of a single driver.
The TCAN1044V transceiver implements a low-power standby (STB) mode which enables a third bus state where the bus pins are weakly biased to ground via the high resistance internal resistors of the receiver. See Figure 12 and Figure 13.