SLLA337A January 2013 – May 2025 SN55HVD233-SEP , SN55HVD233-SP , SN65HVD230 , SN65HVD231 , SN65HVD232 , SN65HVD233 , SN65HVD233-Q1 , SN65HVD234 , SN65HVD234-Q1 , SN65HVD235 , SN65HVD235-Q1 , TCAN330 , TCAN330G , TCAN332 , TCAN332G , TCAN334 , TCAN334G , TCAN337 , TCAN337G , TCAN3403-Q1 , TCAN3404-Q1 , TCAN3413 , TCAN3414
The 3.3V transceivers tested clearly operate in mixed supply networks, which provides advantages. The first advantage is lower power. Not only are 3.3V transceivers lower voltage, they are also lower current.
Table 4-1 shows the supply current for 3.3V devices is reduced by nearly half. Combined with the already lower supply voltage, this results in significant power reduction.
| Case1: 2X SN65HVD234 | SN65HVD234#1 ICC(mA) | SN65HVD234#1 ICC(mA) |
|---|---|---|
| Both recessive | 7.1 | 7.2 |
| #1dominant | 38.4 | 7.2 |
| Both dominant | 25.9 | 26.1 |
| Case2: 2X SN65HVD255 | SN65HVD255#1ICC(mA) | SN65HVD255#1 ICC(mA) |
| Both recessive | 18.6 | 18.6 |
| #1dominant | 61.8 | 18.4 |
| Both dominant | 44.6 | 44.8 |
| Case3: Mixed | SN65HVD234ICC(mA) | SN65HVD255ICC(mA) |
| Both recessive | 7.2 | 18.6 |
| SN65HVD234dominant | 38.6 | 18.6 |
| SN65HVD255dominant | 7.2 | 61.8 |
| Both dominant | 11.7 | 58.9 |
Several other advantages emerge when used with a 3.3V microcontroller. The digital I/O of a 5V transceiver would be level shifted either externally or in the 5V CAN transceiver to avoid damaging the microcontroller (unless it is 5V tolerant) whereas, a 3.3V transceiver could be directly connected to this microcontroller. The SN65HVD233/234/235 3.3V transceivers have 5V tolerant inputs so they may be used directly with a 3.3V or a 5V microcontroller. If 5V was only used in the system for CAN, a 3.3V CAN transceiver would eliminate the need for the 5V power supply, simplifying the power domains and lowering the cost.