Reference design/kit cuts costs of resolver-to-digital conversion

April 14, 2014 // By Graham Prophet
Texas Instruments has introduced a programmable microcontroller (MCU) solution to handle resolver-to-digital decoding: the C2000 Microcontroller (MCU) Resolver Kit. This evaluation kit for resolver-to-digital conversion uses less expensive, programmable C2000 Piccolo MCUs with on-chip ADC and software.

Because the resolver is an analogue, rotary electrical transformer, it has historically required an application-specific circuit — which can be costly and space consuming – to convert to digital signals for use by a digital processor in a control system. TI's C2000 MCU Resolver Kit shows designers how to implement the digital conversion using software on programmable C2000 MCUs, saving system cost and space in a variety of industrial applications, including robotics, servo drives, automation, avionics and transportation.

The C2000 MCU Resolver Kit:

- Replaces expensive, dedicated resolver-to-digital chipsets with low-cost MCUs to simplify and reduce cost in systems.

- Extends functionality by allowing an MCU to handle resolver-to-digital decoding, as well as other software programmable real-time functions, such as additional analogue-to-digital converter (ADC) sampling and processing, encoder and Hall interfaces, digital signal processing (DSP) front-end, state logic, tasks to assist with functional safety and full control loops.

- Provides complete hardware and consists of a C2000 controlCARD-compatible printed circuit board (PCB) with on-board JTAG emulation for software debug, a resolver interface with filtering, UART and SPI interfaces, four digital-to-analogue converter (DAC) outputs for debug and a 15V power supply.

It includes software and hardware development packages:

- Software: Free download of C2000 controlSUITE and Code Composer Studio integrated development environment (IDE), an Eclipse-based IDE for embedded software development.

- Hardware: Full build of materials, schematics and PCB design files.

The kit upports four software project variants running on three different C2000 controlCARDs (all purchased separately):TMDSCNCD28335 (floating-point), TMDSCNCD28035 (fixed-point) or parallel control law accelerator (CLA) and TMDSCNCD28027 (fixed-point).

The C2000 MCU Resolver Kit costs $179; C2000 controlCARDs are available separately starting at $49. The controlSUITE software and documentation are available for download. The C2000 MCUs capable of running the resolver software are available starting from $1.85 (1000).

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