METHOD AND DEVICE FOR INCREASING CONTROL ACCURACY IN A PWM SYSTEM
摘要
<p>A method and a device for operating a bridge power supply circuit comprising at least two switch members connected in series between two rails and operated alternatingly to provide a pulse width modulated output signal at a junction between the two transistors. A measurement circuit measures a voltage drop over the lower switch member during conduction of said switch member. The measurement is performed approximately in the middle of the ON-period and is used in the next cycle for calculating the timing signals. A control signal (Ucontrol) is received at an input for the pulse width modulated output signal. The measured voltage drop is added to the control signal before calculating the timing signals. The voltage drop is scaled by a scaling factor of for example 0.8 before being added to the control signal.</p>