07795828 is referenced by 1 patents and cites 7 patents.

A DC motor comprises a stator having at least three windings coupled to a neutral point; a first pair of upper and lower switches for driving a first winding of the at least three windings to a first voltage or in tristate; a second pair of upper and lower switches for driving a second winding of the at least three windings to a second voltage or in tristate; a third pair of upper and lower switches for driving a third winding of the at least three windings to a third voltage or in tristate, one of the first, second or third windings being in tristate; a back electro-motive force (BEMF) signal generation circuit coupled to receive a BEMF voltage from the winding in tristate; a comparator coupled to receive the BEMF voltage and a zero-crossing voltage representing the voltage at the neutral point at a predetermined time and for comparing the BEMF voltage and the zero-crossing voltage to generate a comparison result; a zero-crossing voltage generation circuit to output the zero-crossing voltage to the comparator; and a commutation controller coupled to receive the comparison result and a speed control signal and for using the comparison result and the speed control signal to generate complementary pulse width modulated (PWM) control signals, one of the complementary PWM control signals for controlling an upper switch and the other of the complementary PWM control signals for substantially simultaneously controlling a lower switch.

Title
Back electro-motive force (BEMF) commutation and speed control of a three-phase brushless DC (BLDC) motor
Application Number
12/56755
Publication Number
7795828 (B2)
Application Date
March 27, 2008
Publication Date
September 14, 2010
Inventor
Yashvant Jani
San Jose
CA, US
Kevin P King
Timberlake
NC, US
Robert Proctor
Durham
NC, US
Agent
Squire Sanders & Dempsey L
Assignee
Renesas Electronics America
CA, US
IPC
H02P 6/18
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