An integrated circuit for controlling operation of a motor of a fan assembly. The fan assembly includes a housing and a fan. The motor is in the housing. The housing is void of sensors. The motor is configured to rotate the fan. The integrated circuit includes a detection module and a first control module. The detection module is separate from the fan assembly. The detection module is configured to detect a voltage induced in a first coil of the motor or a back electromotive force received from the first coil of the motor. The first control module is configured to receive a control signal from a second control module and control the operation of the fan based on (a) the control signal, and (b) the voltage induced in the first coil of the motor or the back electromotive force. The second control module is separate from the integrated circuit.