MC33035/33039 for brushless DC motors control

In the article, firstly it introduces the characteristic as well as its working principle of the chips MC33035 and MC33039 which MOTORALA Corporation specially designs.The design uses the PWM to control the rotational speed, and the Hall which is set in the motor exams rotor position,and the position signal obtained is received by the MC33035,and in the same time MC33035 carries on the decoding to it,in order to determine which pole commutates.In the design it uses the internal differential amplifier to design the way of follower, and the speed command signal directly compares with the saw-tooth wave, which obtains the PWM signal. In order to guarantee the velocity modulation precision request, I use the speed closed-loop control system , and send the rotor position examination signal to MC33039, then transform after the frequency/voltage, which obtain a pulse signal which the frequency is directly proportional to the motor speed, after the filter it is delivered to the negative terminal of MC33035 differential amplifier MC33035, then they compose a regulator, yet the motor speed closed-loop system comes true.