Dalian Dapinjia Group launched an electric toothbrush wireless charging + BLDC solution based on Nuvoton products

As people pay more and more attention to oral hygiene, electric toothbrushes have won the favor of many consumers with their stronger cleaning ability. According to relevant studies, electric toothbrushes can remove 38% more plaque than traditional manual toothbrushes, and the slight vibration generated by its high-speed operation can also promote blood circulation in the oral cavity, which has unexpected effects on gum tissue. massage effect.

On May 6, 2022, Dalian General Holdings, a leading semiconductor component distributor dedicated to the Asia-Pacific market, announced that its subsidiary Pinjia has launched a wireless charging + BLDC solution for electric toothbrushes based on Nuvoton’s MS51FB9AE chip.

Dalian Dapinjia Group launched an electric toothbrush wireless charging + BLDC solution based on Nuvoton products
Figure 1 – The Display board of Dalian Dapinjia’s electric toothbrush wireless charging + BLDC solution based on Nuvoton products

As people pay more and more attention to oral hygiene, electric toothbrushes have won the favor of many consumers with their stronger cleaning ability. According to relevant studies, electric toothbrushes can remove 38% more plaque than traditional manual toothbrushes, and the slight vibration generated by its high-speed operation can also promote blood circulation in the oral cavity, which has unexpected effects on gum tissue. massage effect. Relying on the above characteristics, electric toothbrushes can bring users a better experience in all aspects. The electric toothbrush solution launched by Dalian Dapinjia based on Nuvoton products simplifies the wireless charging of electric toothbrushes and the design of the motor BLDC module, which greatly shortens the user’s research and development time.


Figure 2-Scenario application diagram of Dalian Dapinjia’s electric toothbrush wireless charging + BLDC solution based on Nuvoton products

Nuvoton is an IC design company established in 2008, focusing on the research and development of microcontroller ICs, battery monitoring ICs, image sensing ICs, IoT application ICs, semiconductor components and other products. With flexible technology, advanced design capabilities and superb digital and analog integration capabilities, the company’s products are in a leading position in the industrial, automotive, communications, consumer electronics and computer markets.

This solution uses Nuvoton’s MS51FB9AE microcontroller in the design of wireless power supply, and uses Nuvoton’s proprietary wireless power supply protocol/communication module to make the solution compatible with Qi standard 5W, 7.5W/5W, 15W/5W three types, conversion The efficiency can reach 85%, and it has protection functions such as over-temperature, current limiting, and metal foreign object detection. With this advantage, this solution not only realizes wireless power supply, but also supports two-way information communication. UART data transmission is performed through the primary and secondary coils, and the communication rate can reach 2.4Kbps, which is very suitable for devices that need to communicate between airtight and isolated products.


Figure 3 – Block diagram of Dalian Dapinjia’s electric toothbrush wireless charging + BLDC solution based on Nuvoton products

In the design of BLDC motor, this scheme uses NuMicro®The MS51FB9AE main chip is matched with the NCT3605 gate driver to realize the closed-loop control of the brushless DC motor (Brushless DC, BLDC) system design. The principle of the motor control system is to generate three-phase (U, V, W) duty cycle signals to the gate driver through the 6-channel PWM function, and then control the MOS through the gate driver to drive the motor to rotate. During operation, the system will first use the ADC to sample the voltage of the variable resistor to determine the target speed, and then use the sensor inside the motor to feedback the Hall signal to calculate the actual speed, and feedback compensation through closed-loop control. Therefore, even if the magnitude of the load changes, the target speed can be quickly repaired.

Core technical advantages:

• Rich product resources, one-stop solution to customer product design needs;
• Realize the integration of wireless power supply + wireless UART data transmission;
• Compliant with Qi standard 5W solution, passed Qi Ver 1.1.2 certification (No.: GZES1411013461IT);
• To meet various design requirements, provide open source code of software and hardware for wireless charging and BLDC;
• Convenient localized technical support to solve various technical problems of customers in real time;
• Single chip low cost solution;
• The wireless charging TX side integrates three functions: wireless charging primary coil control, charging current feedback analysis and charging power adjustment;
• The wireless charging RX side integrates three functions: wireless charging receiving, battery charging and discharging management and BLDC motor control.

Program Specifications:

• MS51 (8-bit 1T 8051);
• Flash up to 32 KB; RAM up to 2KB;
• Voltage working range: 2.4V ~ 5.5V;
• Industrial grade working temperature: -40 ~ +105℃;
• Rich peripheral resources: 4 groups of 16-bit Timer, WDT, WKT, UART, SPI, I2C, 3 sets of complementary dual-channel / 6 sets of single-channel output PWM, ADC;
• Excellent ESD&EFT;
• Anti-jamming capability: EFT/4kV & ESD HBM up to 8kV;
• Package support: MSOP10/TSSOP14/QFN20/TSSOP20/TSSOP28/QFN33/LQFP32.

The Links:   SKKD 75F12 LTM220M3-L02