Abstract:
A switched mode power supply device comprising a power transistor periodically set to conduction and supplying a regulated voltage that comprises a ramp generation circuit controlled by a clock signal and periodically generating a ramp voltage. The device includes an amplifier error circuit between a reference voltage and said regulated output voltage and generates an error signal, and a comparator comparing the ramp voltage with said error voltage and providing an output signal for controlling said power circuit. The circuit is characterized in that it comprises a delay element delaying the setting to conduction of the power transistor so as to desynchronize the starting of the ramp and said setting to conduction.
Abstract:
A control device is provided for a switching power supply having an output that supplies an output voltage. The switching power supply includes an inductor and two changeover switches for controlling coupling of the inductor. The control device includes a first capacitor for charging with continuous current from a 0 V voltage level, a second capacitor for discharging of the continuous current from a predetermined voltage level that is greater than the voltage level of a DC power supply, and a comparison circuit. The comparison circuit compares the output voltage of the switching power supply with voltage levels of the first and second capacitors and generates control signals for controlling the two changeover switches of the switching power supply. Also provided are switching power supplies having such control devices and a method for controlling a switching power supply.
Abstract:
The amount of charge passing through a measurement resistor connected to a rechargeable battery is measured by integrating in an analog manner an overall current. This overall current is equal to the sum of the resistor current and of a reference current that selectively takes one of two opposite values. The results of the integration are compared with a reference voltage, and one of two opposite values of the reference current is selected depending on each result of the comparison. The number of times where the positive opposite value of the reference current is selected furnishes an indication on the amount of charge during the integration time.