ARM-core microcontroller for secure, connected, high efficiency motor control

February 25, 2015 // By Graham Prophet
In its presentations of microcontrollers for connected-device applications, Freescale is emphasising its capabilities in providing secure connectivity at all levels. Its Kinetis KV5x MCU family, Freescale asserts, uses the full performance potential of the ARM Cortex-M7 core in the rapidly evolving digital motor control market.

The migration toward digital-based control systems with secure networking capabilities presents a significant opportunity for both energy conservation and end-product feature innovation, that Freescale aims to address with its Kinetis KV5x MCU, combining processing power, sophisticated analogue and timing peripherals, and added connectivity, security and safety features. It claims increased motor efficiency, remote system management and end-node interoperability, via the IoT, to applications from home appliances to complex industrial drives.

The Kinetis KV5x MCU incorporates an IEEE 1588 Ethernet controller, a cryptographic acceleration unit with random number generator, and a memory protection unit. With motors often employed in safety-critical environments such as manufacturing process control, these features allow developers to implement new services via the IoT infrastructure while protecting against erroneous inputs that could lead to an undesired operating condition.

The KV5x has a 240 MHz ARM Cortex-M7 core with single precision floating-point unit. This executes program code from up to 1 MB of on-chip flash memory via a 256-bit wide interface that minimises CPU wait states. 128 kB of data tightly coupled memory (DTCM) and 64 kB of instruction TCM (ITCM) allow high performance deterministic processing, ensuring optimum response for real-time motor speed and position detection. Four high-speed 12-bit ADCs, each capable of 5 Msps, allow the Kinetis KV5x MCU family to support fully asynchronous dual 3-phase motor control with two dedicated ADCs and 8 channel PWMs per motor. Dual 12-channel eFlexPWMs also support 312 picosecond resolution for driving up to eight half-bridge power stages in power conversion applications.

Alongside this announcement, there are several additions to the company's motor control and digital power conversion support:

- FRDM-KV10Z, FRDM-KV31F and FRDM-MC-LVBLDC/PMSM are low-cost Freescale Freedom development platforms for BLDC and PMSM motor control.

- High-Voltage Development Platform – a 115/230V, 1 kW 3-phase motor control software development platform for BLDC, PMSM and ACIM motors of >1Hp, that supports Kinetis KV1x/KV3x/KV4x MCUs and MC56F82748 DSC

- TWR-SMPS-LVFB – a low