Issue link: https://resources.mouser.com/i/1442844
30 Powering Up Your Design Figure 1: Functional block diagram of the PMSM motor controller and drivers. (Source: Qorvo). Design highlights The Qorvo PAC5225 IC, a member of the Qorvo Power Application Controller (PAC) family, is at the heart of the vacuum cleaner project design. This system-on-a-chip (SoC) provides full functionality for building a simple, compact, cost-effective motor control board (Figure 1). The board in this design includes an integrated power management system, a 50MHz, 32-bit Arm ® Cortex ® -M0 microcontroller unit (MCU), gate drivers, operational amplifiers, comparators, and other supporting components. Adding a peripheral MOSFET for delivering constant power output under variable conditions completes the integrated design. Achieving Ultra-High-Speed Motor Operation Exceptional motor speed was an essential design parameter in this project, aiming to reach levels substantially higher than standard vacuum cleaners on the market. To achieve a mechanical speed of up to 150,000rpm required closely managing operation of the analog-to-digital converter (ADC) and the pulse-width modulator (PWM), which the Arm ® Cortex ® -M0 MCU controls. The electrical frequency required can range up to 2.5kHz, and—for precision FOC control—the ADC sampling speed and accuracy must be up to 1MSPS, and very fine resolution of the PWM is needed. The microcontroller ensures that these values are finely tuned for precise operation., The FOC algorithm developed by Qorvo is customized to meet these requirements and accelerate the FOC's operational sequences. Regulating Power for Optimal Results Many different factors affect suction in a vacuum cleaner, including air duct volume of different attachments, battery levels, any ingested object that clogs the vacuum, and the exhaust filter getting saturated with dust and debris. This is where maintaining constant power under changing conditions is critical to maximizing suction. Designs based on the regulation of torque or motor speed don't respond as well to the full range of factors affecting suction strength, whereas regulating power—as monitored by microcontroller integrated into the SoC and controlled by the custom Qorvo FOC algorithm—delivers far more consistent results. Calculations are performed in real-time, using internal power-level data sampled by the ADC, and necessary power adjustments can be made rapidly.