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Fan Controller | Cypress Semiconductor

Fan Controller

Last Updated: 
Jun 11, 2013

Supported Devices: CY8C23x33, CY8C24x23, CY8C24x33, CY8C24x94, CY8C27x43, CY8C28xxx, CY8C29x66

General Description:

The Fan Controller User Module in PSoC Designer helps you control up to eight, four-wire fans in open-loop or closedloop mode. The Fan Controller User Module wizard enables you to select the number of fans and their configurations. Some key applications of Fan Controller are in servers, computers, projectors etc.

The Fan Controller User Module changes the fan speed using hardware PWMs implemented in programmable digital blocks in PSoC 1. It measures fan speed by reading tachometer output using a 16-bit timer and a hysteresis comparator.

In open-loop mode, PSoC 1 sets the user defined PWM duty cycle irrespective if the current fan speed. However, application programming interface (API) is provided to measure the fan speed. In closed-loop mode, a desired fan speed is achieved by PSoC 1 by controlling PWM duty cycle based on the difference between desired and current speed. In open-loop mode, this User Module supports multiple fans to be connected to the same PWM signal called “banks”.



  • Open-loop and closed-loop control of four-wire BLDC fans
  • User Module wizard to select the number of fans and their configuration
  • Fan speeds ranging from 450 to 25,000 RPM
  • Fan stall/rotor lock condition detect on all fans
  • Selectable tolerance and damping factor
  • Multiple fans grouped together called “banks” can be connected to one PWM output
  • APIs to set desired speed and to read current speed


Fan Controller Wizard

Related Pages: Application Notes, Technical Reference Manuals, Design Guides