The SN65HVD233 is used in applications employing the
controller area network (CAN) serial communication physical layer in accordance with the ISO 11898
standard, with the exception that the thermal shutdown is removed. As a CAN transceiver, the device
provides transmit and receive capability between the differential CAN bus and a CAN controller,
with signaling rates up to 1 Mbps.
Designed for operation in especially harsh environments, the device features cross wire,
overvoltage, and loss-of-ground protection to ±36 V, with common-mode transient protection of
±100 V. This device operates over a –7-V to 12-V common-mode range with a maximum of 60 nodes on a
bus.
If the common-mode range is restricted to the ISO 11898 standard range of –2 V to 7 V, up
to 120 nodes may be connected on a bus. This transceiver interfaces the single-ended CAN controller
with the differential CAN bus found in industrial, building automation, and automotive
applications.
RS (pin 8) provides for three modes of operation: high-speed,
slope control, or low-power standby mode. The high-speed mode of operation is selected by
connecting RS directly to ground, thus allowing the driver output
transistors to switch on and off as fast as possible with no limitation on the rise and fall slope.
The rise and fall slope can be adjusted by connecting a resistor to ground at
RS, because the slope is proportional to the output current of the pin.
Slope control is implemented with a resistor value of 10 kΩ to achieve a slew rate of
≉ 15 V/µs, and a value of 100 kΩ to achieve ≉ 2 V/µs slew rate. For more information about
slope control, refer to the Application and Implementation section.
The SN65HVD233 enters a low-current standby mode, during which the driver is switched off
and the receiver remains active if a high logic level is applied to RS. The
local protocol controller reverses this low-current standby mode when it needs to transmit to the
bus.
A logic high on the loopback (LBK, pin 5) of the SN65HVD233 places the bus output and bus
input in a high-impedance state. The remaining circuit remains active and available for the driver
to receiver loopback, self-diagnostic node functions without disturbing the bus.
