Humidifiers are able to refresh air and relieve dryness in a room as well as remove floating particles from the air. They are widely used to regulate the humidity of household or commercial space areas and thus create a comfortable and healthy environment.

Holtek has developed Ultrasonic Humidifier Flash MCUs, the HT45F3820 and the HT45F3830. When compared with traditional MCU solutions for humidifier applications, this device series has an internal diaphragm vibrating frequency control module, water depletion detection function and provides large I/O output current which can directly drive external power transistors. In addition, they use a new high-power nebuliser application design which allows for simultaneous implementation of higher operation efficiencies with no heat dissipation issues.
Holtek provides circuits, application block diagram, PCBs and a component list in this reference design. More information about the competitive advantages of this humidifier solution can be obtained by clicking on the “Learn more about our application solutions”.


Application Areas

Ultrasonic Humidifiers


Minimal external components and lower costs

Includes integrated diaphragm vibrating frequency control module and a powerful drive capability which can directly drive external power transistor resulting in reduced costs of the components such as dry reed, transistor radiator and etc.


High level of functional integration and wide applications

Includes an integrated high accuracy RC oscillator and multiple timer modules, provides PWM output function for implementing LED intensity/colour adjustment functions.



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System Architecture and Connection Diagram

This application solution provides a reference design which is a highly integrated solution using very few external components. It includes a power supply circuit, reference voltage circuit, keys, nebuliser and fan module etc. This application shows a complete humidifier reference design solution.

(C20011-A.ZIP) humidifiers main control board
Description Files   Solution Description and Application Notes
Application Circuits Protel format
PCB Protel format
Block Diagram PDF
Code   Source code
Component List   Excel format


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