Patent ID: 6061258
Filing Date: 2000-05-09
Classification: H02M,H02P

Abstract:
A method of monitoring current flowing through an inductive load driven through a bridge power stage in a pulse width modulation (PWM) mode, the method comprising the steps of:amplifying by a sensing amplifier a signal existing on a current sensing resistor functionally connected in series with the inductive load to produce an amplified signal representative of the current in the inductive load;feeding the amplified signal to an input of an error amplifier for driving a power amplifier of the bridge power stage;sampling the amplified signal from the sensing amplifier using a sample and hold circuit comprising a sampling switch and a storing capacitor; andmonitoring an average value of current in the inductive load by sampling at a half way instant of an active driving phase and at a half way instant of a current recirculation phase by closing the sampling switch based upon a synchronizing pulse that coincides with the half way instants of the active driving and current recirculation phases.