New microcontrollers help lower system cost and complexity in resolver-based motor control systems

September 28, 2012 // By Paul Buckley
Texas Instruments Incorporated has introduced 32-bit C2000 Delfino microcontrollers as resolver-to-digital converter interfaces for motor control systems, lowering system cost while delivering more efficient motor control capabilities.

The high-performance, floating-point Delfino microcontrollers with an on-chip, high-precision analog-to-digital converter, along with an external low-cost signal conditioning circuit, provide motor control designers an alternative to more expensive and complex semiconductor solutions.

 Both resolvers and encoders are used in typical precision servo motor control systems, such as industrial drives and automotive power steering and traction control. Resolvers and encoders provide shaft position feedback to the control unit, but resolvers are highly accurate and noise immune, proving more robust and rugged than encoders.  However, resolvers require a special precision resolver-to-digital converter to interface to a digital control system. These converters add complexity and cost to the motor control solution.  Delfino microcontrollers can duplicate this functionality of producing the excitation signal and sampling and processing the feedback to obtain the angular reading as part of the motor control algorithms executed by these devices without the need for a dedicated resolver-to-digital converter, allowing advanced torque, speed and position control to be achieved with even greater accuracy. In addition, optimized Delfino microcontroller resolver software to ease development is available for free from TI.

The Delfino microcontroller offers an 300 MHz C28x core that provides fast interrupt response, minimal latency, execution of complex control algorithms and real-time data analysis.  The 32-bit floating-point unit eases programming of magnitude calculations, eliminates scaling and saturation burden and improves performance of algorithms such as Park transforms and proportional integral derivatives (PID). Up to 516 KB of on-chip, single-cycle access RAM enables high-speed program execution and data access.  Up to 65ps flexible, high-resolution pulse-width modulators (PWMs) allow for optimal precision.

An internal 12-bit,  12.5 MSPS ADC and the option for an external ADC with the analog-to-digital converter (ADC) interface gives developers flexibility to use the on-board ADC or  select from TI's broad portfolio of high-accuracy ADCs, such as the ADC161S626, ADS1205 and ADS1209.

Availability and Pricing

Delfino microcontrollers start at $8.95 in quantities of 1,000 units.

More information about TI's