The part you mentioned, "SN65HVD72DR," is manufactured by Texas Instruments. It is a high-speed CAN (Controller Area Network) transceiver designed to interface with microcontrollers and other CAN bus components in automotive and industrial applications.
Package and Pinout
The SN65HVD72DR comes in a SOIC-8 (Small Outline Integrated Circuit) package. It has 8 pins in total, and each pin serves a specific function related to CAN communication. Below is a detailed explanation of the functions for each of the 8 pins.
Pinout and Function List for SN65HVD72DR:
Pin Number Pin Name Pin Function Description 1 Vcc Power supply pin. Provides voltage to the device. Typically 5V or 3.3V depending on the application. 2 TXD (Transmit Data) Input pin for transmitting CAN data from the microcontroller to the CAN transceiver. A low-level signal (logic 0) indicates that data is being transmitted. 3 RXD (Receive Data) Output pin for receiving CAN data from the bus to the microcontroller. It carries the decoded signals for the CAN communication. 4 CANH (CAN High) CAN bus differential high signal. This pin connects to the CAN network's high-side line. The voltage level fluctuates with data transmission on the network. 5 CANL (CAN Low) CAN bus differential low signal. This pin connects to the CAN network's low-side line. The voltage level fluctuates in opposition to CANH. 6 GND Ground pin. Provides the common ground reference for the device, connecting to the system's ground. 7 RTER (Remote Transmission Request) Optional pin for controlling transmission based on remote requests in a CAN network. 8 NC (No Connect) This pin is not connected to any internal circuit or function. It is reserved and should not be used.Pin Function Detailed Explanation:
Vcc (Pin 1): This is the power supply pin. The voltage applied to this pin determines the operational logic level of the device. The SN65HVD72DR operates typically at 5V, but certain variants or systems may support lower voltages.
TXD (Pin 2): The TXD pin is used for sending data from a microcontroller or processor to the CAN transceiver. It is typically connected to the UART or CAN controller of the microcontroller. When the controller wishes to send data on the CAN bus, it will drive a signal on this pin to indicate the message.
RXD (Pin 3): The RXD pin receives data from the CAN bus. When a message is transmitted on the CAN network, the CAN transceiver decodes the signal and outputs it as a digital signal to the microcontroller.
CANH (Pin 4): The CANH pin represents the CAN network's high voltage differential signal. In a CAN network, two signals (CANH and CANL) are transmitted differentially. The CANH pin carries the higher voltage during data transmission.
CANL (Pin 5): The CANL pin carries the complementary low voltage signal of the differential pair. It works together with CANH to ensure reliable communication across the network, providing fault tolerance and noise immunity.
GND (Pin 6): This is the ground pin. Proper grounding is essential for the device to function correctly, ensuring that the signals are referenced properly to the system ground.
RTER (Pin 7): The RTER pin is used for remote transmission requests, typically used in systems where remote nodes may request data to be transmitted.
NC (Pin 8): The NC pin is a no-connect pin, meaning it is reserved and should not be used or connected to any external circuitry.
FAQs for SN65HVD72DR:
Q: What is the supply voltage for the SN65HVD72DR? A: The supply voltage (Vcc) for the SN65HVD72DR is typically 5V, though certain versions may support a 3.3V operating voltage.
Q: How does the RXD pin work? A: The RXD pin receives CAN data from the bus, converting it into a digital signal that is passed to the microcontroller for processing.
Q: Can the SN65HVD72DR operate on 3.3V logic? A: Yes, the SN65HVD72DR can operate with a 3.3V logic level depending on the system design, but it typically operates at 5V.
Q: How do the CANH and CANL pins communicate data? A: The CANH and CANL pins communicate data using a differential signal. CANH carries the high voltage, and CANL carries the low voltage, providing noise immunity and robust communication.
Q: What is the purpose of the RTER pin? A: The RTER pin handles remote transmission requests, which is used in some applications where a remote node requests data transmission.
Q: What is the maximum data rate supported by the SN65HVD72DR? A: The maximum data rate supported is 1 Mbps, which is typical for high-speed CAN communications.
Q: What is the typical usage scenario for the SN65HVD72DR? A: The SN65HVD72DR is typically used in automotive and industrial applications that require communication over the CAN bus, such as connecting microcontrollers to a CAN network.
Q: How should the CANH and CANL pins be routed in a PCB design? A: The CANH and CANL pins should be routed as differential pairs with proper impedance matching (usually around 60 ohms) to ensure signal integrity.
Q: Can the SN65HVD72DR be used in high-noise environments? A: Yes, the SN65HVD72DR is designed for robust communication in noisy environments, especially automotive and industrial applications, due to the differential signaling on the CANH and CANL lines.
Q: How does the TXD pin function during communication? A: The TXD pin is driven by the microcontroller to send data to the CAN bus. It is a logic-level output that communicates with the SN65HVD72DR to transmit messages on the CAN network.
Q: What is the output voltage level on the RXD pin? A: The RXD pin outputs a logic-level signal that represents the received data from the CAN bus, typically either 3.3V or 5V depending on the system's logic level.
Q: What are the typical applications of the SN65HVD72DR? A: The SN65HVD72DR is commonly used in automotive electronics, industrial control systems, and other embedded applications that use CAN communication protocols.
Q: Is the SN65HVD72DR compatible with CAN FD (Flexible Data-rate)? A: No, the SN65HVD72DR is not compatible with CAN FD. It supports only the standard CAN protocol.
Q: What is the function of the NC pin? A: The NC (No Connect) pin is reserved and should not be connected to anything. It is not used for any electrical function.
Q: How should I connect the GND pin in my circuit? A: The GND pin should be connected to the ground of the system to ensure proper functioning of the SN65HVD72DR.
Q: Can the SN65HVD72DR be used with a microcontroller without a CAN controller? A: Yes, the SN65HVD72DR can interface directly with a microcontroller, but the microcontroller must support CAN communication either natively or through an external CAN controller.
Q: What type of protection is built into the SN65HVD72DR for the CANH and CANL lines? A: The device includes integrated protection circuitry for the CANH and CANL pins, protecting against short circuits and voltage spikes.
Q: Can the SN65HVD72DR be used in both 3.3V and 5V systems? A: Yes, the SN65HVD72DR can be used in both 3.3V and 5V systems, but care must be taken to ensure proper voltage levels for the CAN bus signaling.
Q: What type of CAN network does the SN65HVD72DR support? A: The SN65HVD72DR supports standard CAN networks (ISO 11898-1), which are widely used in automotive and industrial applications.
Q: What is the typical package size for the SN65HVD72DR? A: The SN65HVD72DR typically comes in an 8-pin SOIC package, which is a small surface-mount package ideal for space-constrained designs.
This should provide a comprehensive view of the SN65HVD72DR transceiver's pin functions, packaging, and frequently asked questions.
