The SN65HVD233-Q1, SN65HVD234-Q1, and SN65HVD235-Q1 devices are fault-protected 3.3-V CAN
transceivers that are qualified for use in automotive applications. These transceivers work from a
3.3-V supply and are ideal for systems that also leverage a 3.3-V microcontroller, thereby reducing
the need for additional components or a separate supply to power the controller and the CAN
transceiver. The SN65HVD23x-Q1 transceivers are compatible with the ISO 11898-2 standard and thus
are interoperable in mixed networks that employ 5-V CAN and/or 3.3-V CAN transceivers.
Designed for operation in especially harsh environments, the devices feature crosswire
protection, overvoltage protection on the CANH and CANL pins up to ±36 V, loss-of-ground
protection, overtemperature (thermal shutdown) protection, and common-mode transient protection of
±100 V. These devices operate over a wide –7-V to 12-V common-mode range. These transceivers are
the interface between the host CAN controller on the microprocessor and the differential CAN bus
used in transportation and automotive applications.
Modes: The RS pin (pin 8) of the SN65HVD233-Q1,
SN65HVD234-Q1, and SN65HVD235-Q1 devices provides three modes of operation: high-speed, slope
control, and low-power standby mode. The high-speed mode of operation is selected by connecting pin
8 directly to ground, 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 between the RS pin and ground. The slope is proportional to the output
current of the pin. With a resistor value of 10 kΩ the device driver has a slew rate of
approximately 15 V/µs, and with a value of 100 kΩ the device has a slew rate of approximately 2
V/µs. For more information about slope control, see Feature Description.
The SN65HVD233-Q1, SN65HVD234-Q1, and SN65HVD235-Q1 devices enter a low-current standby
(listen-only) mode during which the driver is switched off and the receiver remains active if a
high logic level is applied to the RS pin. If the local protocol controller must transmit a message
to the bus, it must return also the device to either high-speed mode or slope-control mode via the
Loopback (SN65HVD233-Q1): A logic high on the loopback
(LBK) pin (pin 5) of the SN65HVD233-Q1 device places the bus output and bus input in a
high-impedance state. Internally, the TXD-to-RS path of the device remains active and available for
driver-to-receiver loopback that can be used for self-diagnostic node functions without disturbing
the bus. For more information on the loopback mode, see Feature Description.
Ultralow-Current Sleep (SN65HVD234-Q1): The
SN65HVD234-Q1 device enters an ultralow-current sleep mode in which both the driver and receiver
circuits are deactivated if a low logic level is applied to EN pin (pin 5). The device remains in
this sleep mode until the circuit is reactivated by applying a high logic level to pin 5.
Autobaud Loopback (SN65HVD235-Q1): The AB pin (pin 5)
of the SN65HVD235-Q1 device implements a bus listen-only loopback feature which allows the local
node controller to synchronize its baud rate with that of the CAN bus. In autobaud mode, the bus
output of the driver is placed in a high-impedance state while the bus input of the receiver
remains active. There is an internal TXD pin to RS pin loopback to assist the controller in baud
rate detection, or the autobaud function. For more information on the autobaud mode, see Feature Description.