Analog Devices, Inc. (ADI) and Minebea Co., Ltd. of Japan, are jointly developing high-performance resolver systems that will be offered at a lower price than commonly found in the automotive industry. According to the companies, the systems will be affordable and easy to use for high-volume applications such as electric power steering (EPS), starters/generators, and hybrid-electric vehicles. EPS systems have many benefits to consumers because they enable environmentally friendly vehicles and can save drivers up to 8% on fuel economy.
ADI will supply resolver-to-digital converter (RDC) integrated circuits to Minebea for use with its family of resolvers. Minebea will market and sell the solution. A resolver is a mechanical device mounted on a rotating shaft of a motor to give the exact position of the shaft in the form of sine and cosine signals. An RDC converts this information into digital signals for the controller. ADI's RDCs perform this conversion in hardware and also give velocity, direction outputs, as well as encoder emulation.
"We chose to partner with Analog Devices because the company has the integrated circuit expertise in resolver-to-digital converter technology, motor control, and DSP we were in search of," said Akihiro Hirao, Director, General Manager, Office of Engineering Department, Minebea.
"We believe that Minebea's experience in building quality, high-volume resolvers, combined with Analog Devices' record of delivering industry-leading resolver-to-digital converter technology, will result in the platform of choice in high-precision motor control," said Phil Davies, Director, Embedded
Digital Signal Processor Division, Analog Devices ADI is currently developing two versions of 12-bit RDCs to use with Minebea's resolvers. Both components will be rated for automotive temperature and environments ranging from -40 to +125°C (-40 to +257°F) for the highest levels of quality and reliability. The resolver system sends its position, velocity, and direction information via a parallel or serial port, resulting in easy adoption of the new technology to existing EPS systems and enabling much higher performance at lower costs. In addition, the resolver system will interface with microprocessor-based motor controllers, including ADI's families of embedded DSP motor controllers, such as the ADMCxxx and future ADMC5xx families.
Jean L. Broge
AEI October 2000
