More and more embedded-system designers are looking to make the transition to 32-bit, DSP-based controllers from earlier 8- and 16-bit MCU-based designs. In adding four new members to its TMS320F280xx family of DSP controllers, Texas Instruments is taking aim at motor control, digital power conversion, and intelligent sensor control applications. Starting as low as $3.25 each in lots of 1000, the TMS320F28015 and -F28016 controllers deliver 60-MHz performance. For their part, the TMS320F2801-60 and -F2802-60 controllers offer similar speed and are based on the current TMS320F2801 and -F2802 devices.
Within the F280xx controller series is a portfolio of eleven software and pin-for-pin compatible devices with 32-bit DSP performance combined with the peripheral integration and ease-of-use of an MCU. All F280x- based devices feature a 32-bit-wide data path and a mixed 16/32-bit instruction set for improved code density. These controllers offer complete control system capabilities from signal input through the on-chip, 12-bit ADC, quadrature encoder pulse (QEP) interfaces, and timer captures and compares through signal output with up to 10 independent PWM channels. Depending on the device, communication interfaces include CAN, I2C, UART, and SPI ports.
All four new F280x devices feature a PWM with 150-ps resolution. The PWM provides 16 bits of accuracy in a 100-KHz control loop and 12 bits at 1.5 MHz. As a result, power developers are able to achieve cleaner power output, higher power density, smaller magnetics, and more compact, cooler supplies. These characteristics can be critical in applications like AC/DC rectifiers that require high tolerances and faster transient response with small ripple amplitude. For motor-control applications such as white goods and automotive systems, designers can reduce overall system costs while leveraging the 32-bit performance necessary to implement advanced control techniques like sensorless vector control of three-phase motors. Using processor-intensive sensorless vector control can help developers to reduce the size and cost of a system's motors and power electronics required to meet their needs.
Also available is a digital-power development kit that’s targeted initially at ac-dc rectifier and dc-ac inverter applications. The kit, which includes the digital power system (DPS) software library and DPS hardware modules, includes reference software for key functions used in an ac-dc rectifier, solar energy inverter, and UPS applications. Written in optimized C, the software is fully documented to aid engineers new to digital control of power supplies and allow them to translate their analog experience into the digital realm. DPS library components available today include two-phase boost power factor correction (PFC), multi-channel dc-dc conversion, and a single-phase dc-ac inverter with additional software components to be added. The DPS library can be downloaded for free at www.ti.com/dpslib.
The DPS hardware modules, which are produced by Tier Electronics, help engineers to start working on F280x controller-based digital power designs quickly without having to build their own controller or power-stage hardware. The first two modules in the kit are targeted at PFC and dc-dc converter designs. The PFC module is a two-phase boost topology while the dc-dc module is a dual phase-shifted full-bridge topology. Each board is available individually for $295 directly from Tier at www.tierelectronics.com and connects easily to TI's TMS320F2808 eZdsp development kit, which provides the controller hardware. The DPS hardware modules can be controlled individually by the eZdsp or connected together for an ac-dc rectifier application. The TMS320F2808 eZdsp development kit (TMDSEZS2808) is available for $495 from Texas Instruments. The DPS hardware modules will be available from Tier starting in late September.