Overview
Every electronic product needs power conversion, and the efficiency of that conversion affects both the electricity bill and the size of the product. Switch-mode supplies, DC-DC converters and power factor correction stages all depend on efficient switching devices and, increasingly, on digital control that can adapt and report. BeiLuo supplies the STMicroelectronics STPOWER MOSFETs and STM32 microcontrollers that make these designs work, as an authorized STMicroelectronics distributor with FAE support for power design.
The Switching Device
The heart of a switching supply is the MOSFET that chops the input voltage. Its on-resistance determines conduction loss, which dominates at low switching frequency, and its gate charge determines switching loss, which dominates at high frequency. The design task is to balance the two against the frequency and the loss budget. For low-voltage, high-current stages, a low-resistance part such as the STP110N8F6 keeps conduction loss small. For higher voltages and ruggedness, parts such as the STP60NF06 and ST's MDmesh super-junction devices offer a balance suited to offline supplies, and SiC MOSFETs serve the highest-voltage, highest-efficiency designs.
Topology and Frequency
The topology sets the voltage and current the switch must handle and the frequency at which it switches. Higher frequency shrinks the magnetics but raises switching loss, so the switch and the topology are chosen together. A flyback, a forward converter and an LLC resonant stage each place different demands on the device.
Digital Control
Digital control on an STM32 microcontroller gives a supply flexibility that analog control cannot match. The control loop can be tuned in firmware, the supply can report its status over a communication interface, and features such as soft start and protection can be added without extra components. The STM32 family provides the timers, ADCs and DACs that digital power design needs, and the STM32Cube ecosystem supplies the libraries. The main design task is the power supply and analog reference of the microcontroller itself, which is covered in our STM32 power design application note.
Measuring and Protecting
A digital supply measures its own voltages and currents, which allows it to protect the load and to report faults. The accuracy of those measurements depends on the ADC reference and the layout, so the analog supply and grounding of the microcontroller matter as much as the power stage.
Layout and Thermal
Power conversion layout is unforgiving: the switching loop must be small to limit radiated EMI, the ground return must be solid, and the switch must have a good thermal path. Poor layout raises loss, EMI and temperature at once. BeiLuo's FAE team reviews power-stage layout and thermal design during design-in and can validate the result in our lab.
Why BeiLuo
We hold mainstream STPOWER and STM32 parts in regional stock and ship them with import, origin and RoHS documentation. Our engineers support device selection, gate drive, layout and thermal design, and can supply samples for bench validation before production.
Next Steps
Send your input and output range, power level and topology and we will propose a device set, confirm availability, and supply samples for validation.