Datasheet

RXD
V
CC
/2
CANH
CANL
GALVANIC
ISOLATION
Recessive
Logic H
Dominant
Logic L
Recessive
Logic H
Time, t
Typical Bus Voltage (V)
Normal & Silent Mode
CANL
CANH
V
diff(D)
V
diff(R)
4
3
2
1
ISO1050
www.ti.com SLLS983H –JUNE 2009–REVISED JUNE 2013
FUNCTIONAL DESCRIPTION
CAN BUS STATES
The CAN bus has two states during operation: dominant and recessive. A dominant bus state, equivalent to logic
low, is when the bus is driven differentially by a driver. A recessive bus state is when the bus is biased to a
common mode of V
CC
/ 2 via the high-resistance internal input resistors of the receiver, equivalent to a logic high.
The host microprocessor of the CAN node will use the TXD pin to drive the bus and will receive data from the
bus on the RXD pin. See Figure 1 and Figure 2.
Figure 1. Bus States (Physical Bit Representation)
Figure 2. Simplified Recessive Common Mode Bias and Receiver
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