FROM EDN EUROPE: Improve CAN's tolerance of noisy conditions

You can achieve a higher level of reliability in CAN (controller-area-network)-bus systems in industrial and automotive environments using a new transceiver from Texas Instruments.

The device operates in noisy industrial conditions, and you can use it with any CAN controller operating at 3.3 or 5V. The SN65HVD251 has ESD (electrostatic-discharge) protection to 12 kV and withstands bus-fault conditions, such as crossed wires, overvoltage, or loss of ground reference, as high as ±36V.

It implements differential signalling on the bus at speeds as high as 1 Mbps and, when unpowered, is transparent to the rest of the devices on the bus. High input impedance allows for buses supporting as many as 120 nodes. The device costs 82 cents (1000).

For economical signal processing on the logic side of your system, TI offers another price-performance point for its TMS320C55 DSP family: a dual-MAC (media-access-controller), 300-MHz device for $5 (10,000). You can use the C5501 over the industrial-temperature range of –40 to +85°C, and it uses approximately 200 mW. It has 16k words of dual-access RAM and 16k words of ROM onboard. A unified-memory architecture allows the use of low-cost external memory. The 5501 will become available for sampling after midyear.

TI is also offering the 5502, which offers double the on-chip memory at 32k words, for $9.95. The 5502 variant will be available for sampling in the next few weeks. As with other 320-series DSPs, the devices offer code compatibility with earlier chips and have support from the TI design suite, including Code Composer Studio. TI will run a series of one-day C55 workshops in a number of international locations beginning in the next few weeks; details are on the company's Web site.

Texas Instruments, +49 8161 80 33 11, www.ti.com.