Single-shunt BLDC motor controller cuts system footprint and BOM

Aimed at the growing market of battery-operated power tools, the STSPIN32F0B motor controller integrates a single op-amp for current sensing, which saves individual 3-phase BLDC coil-current sense resistors and makes extra I/O pins available for user features. The new SiP contains a 48MHz STM32F031x6 MCU capable of running a 6-step motor-control algorithm as well as other application-level functionalities.

With 20 GPIO pins the STSPIN32F0B allows easy access to the MCU’s internal features that include up to five general-purpose timers, a 12-bit ADC and a temperature sensor. The MCU also provides I2C, UART, and SPI ports. The chip contains a triple half-bridge gate driver capable of sourcing up to 600mA per channel into external MOSFETs for powering the motor.

In addition, a 3.3V DC/DC buck converter and 12V low-dropout (LDO) regulator provide the voltage rails to supply the MCU, gate driver, and external components, further reducing the bill of materials and enhancing overall system efficiency.

Other integrated features include bootstrap diodes for reliable startup and real-time programmable over-current protection, cross-conduction/shoot-through prevention, under-voltage lockout (UVLO) on all power supplies, and over-temperature protection.

ST provides a selection of ready-to-use 6-step motor-control algorithms for sensored or sensorless BLDC control, as part of a complete set of hardware, software, and firmware tools that simplify and streamline new-product development. The 7x7mm QFN package operates from 45V down to 6.7V.