Startup Circuit of Sensorless Brushless DC Motors with Stabilized Switching Behavior of the Drive

摘要

The present invention relates to a sensorless brushless DCM motor (hereinafter referred to as SLBLDC motor), and in particular, a start-up of a Waltz Step Start (WSS) method. The equation relates to a start-up circuit for a sensorless brushless DC motor in which the drive's switching behavior is stabilized.;The present invention provides a power supply logic circuit for outputting three pairs of three-phase control signals in response to a clock signal; A gate circuit unit for gating the three pairs of three-phase control signals such that the control signals of each phase transition from a low state to a high state through an intermediate state in response to the clock signal; And an output drive for outputting a three-phase drive signal of a motor in response to the three-pair three-phase control signals so that the three-pair three-phase control signals remain in an intermediate state when the output signal passes through the gate circuit unit. Characterized in that the circuit portion, it is possible to extend the life of the motor because the transistor in the output driving circuit portion is not damaged at start-up, since a section in which two power transistors according to each phase is turned on at the same time does not occur.