Abstract: A digital voltage regulator has an input terminal coupled to an input voltage source, an output terminal coupled to a load, and a plurality of switching circuits to alternately couple and decouple the input terminal to the output terminal. An estimated current is calculated for each switching circuit, each estimated current representing a current passing through an inductor associated with the switching circuit. A total desired output current to pass through the inductors is calculated which will maintain an output voltage at the output terminal substantially constant. The switching circuits are controlled based on the estimated current and the total desired output current so that a total current passing through the inductors is approximately equal to the total desired output current.

Abstract: A voltage regulator with an input terminal to be coupled to an input voltage source and an output terminal to be coupled to a load. The voltage regulator has a first switch to intermittently couple the output terminal to the input terminal, a voltage sensor to detect a voltage at the output terminal, a current sensor to detect a current flowing along a circuit path between the input terminal and the output terminal, and a controller connected to the switch, the voltage sensor and the current sensor. The controller is configured to close the first switch if the voltage is less than a first threshold voltage and the current is less than a first threshold current, and the controller is configured to open the first switch if the voltage is greater than a second threshold voltage and the current is greater than a second threshold current.

Abstract: A digitally implemented voltage regulator in which a switching circuit intermittently couples the input terminal and the output terminal in response to a digital control signal. A current sensor generates a digital first feedback signal derived from the current passing through the switching circuit, and a voltage sensor generates a digital second feedback signal derived from the output voltage. A digital controller receives and uses the digital feedback signals to generate the digital control signal.

Abstract: A voltage regulator with an input terminal and an output terminal has a printed circuit board, a substrate mounted on the printed circuit board, and a first flip-chip type integrated circuit chip mounted on the substrate. The first integrated circuit chip includes a first power switch fabricated therein to alternately couple and decouple the input terminal to the output terminal. A filter is disposed to provide a substantially DC voltage at the output terminal, and a control circuit controls the power switch to maintain the DC voltage substantially constant.

Abstract: A switching regulator has first, second, third and fourth terminals. The switching regulator includes a power switch, a rectifier switch, a filter, a shorting switch and a controller operable in a plurality of modes to open and close the switches. The power switch is disposed between the first terminal and a first node, and the rectifier switch is disposed between the first node and a second node coupling the second and fourth terminals. An inductor is disposed between the first node and the third terminal. One or more shorting switches can be connected in parallel with the inductor.

Abstract: A digitally implemented voltage regulator in which a switching circuit intermittently couples the input terminal and the output terminal in response to a digital control signal. A current sensor generates a digital first feedback signal derived from the current passing through the switching circuit, and a voltage sensor generates a digital second feedback signal derived from the output voltage. A digital controller receives and uses the digital feedback signals to generate the digital control signal.

Abstract: A voltage regulator with a switch to alternately couple and decouple an input terminal to an output terminal with a variable duty cycle and a filter disposed between the input terminal and the output terminal to provide a substantially DC voltage at the output terminal. A sampling circuit makes measurements of an electrical characteristic of the voltage regulator at discrete moments of time, such as just before the opening and closing of the switch. A feedback circuit is coupled to the sampling circuit and the switch, and is configured to use the measurements to control the duty cycle to maintain the DC voltage substantially constant. The feedback circuit uses the switch as the resistive element in order to measure the current passing through the voltage regulator.

Abstract: A digital control system for a voltage regulator calculates an estimated current representing a current passing through each inductor associated with a switching circuit. A desired total output current is calculated which will maintain an output voltage at the output terminal at a substantially constant level. Upper current limit and a lower current limit are calculated and the switching circuit to is caused couple an input terminal to an output terminal when the estimated current falls below the lower current limit, and caused to couple the output terminal to ground when the estimated current exceeds the upper current limit. Also, the estimated current may be compared to an individual current to trigger the switching circuit.

Abstract: A sensor for measuring a current passing through a load. The sensor has a power transistor having a first terminal connected to substantially constant voltage and a second terminal connected to the load. The sensor can sample a voltage difference with a variable capacitor, and a controller can be configured to cause a variable capacitor in the current sensor to have a capacitance inversely proportional to a resistance of the power transistor, whereby a charge stored on the variable capacitor is proportional to the current passing through the power transistor when the sampling switches are opened. A comparator can compare the current through the power transistor to a known reference current to generate a digital output signal. The sensor can include a power transistor, reference transistor and amplifier connected and configured so as to generate a signal on a reference line having a current of known proportion to the current passing through the load.

Abstract: A digital voltage regulator has an input terminal coupled to an input voltage source, an output terminal coupled to a load, and a plurality of switching circuits to alternately couple and decouple the input terminal to the output terminal. An estimated current is calculated for each switching circuit, each estimated current representing a current passing through an inductor associated with the switching circuit. A total desired output current to pass through the inductors is calculated which will maintain an output voltage at the output terminal substantially constant. The switching circuits are controlled based on the estimated current and the total desired output current so that a total current passing through the inductors is approximately equal to the total desired output current.

Abstract: A method of estimating a current passing through an inductor in a voltage regulator in which an initial estimated current is stored representing the current flowing through the inductor, and the initial estimated current is adjusted based on the status of the switching circuit in the voltage regulator to generate a new estimated current. An incremental current is added to the initial estimated current if an output terminal is coupled to an input terminal, and a decremental current is subtracted from the initial estimated current if the output terminal is coupled to ground. The estimated current can be used for controlling the switching circuit.

Abstract: A voltage regulator with a switch to alternately couple and decouple an input terminal to an output terminal with a variable duty cycle and a filter disposed between the input terminal and the output terminal to provide a substantially DC voltage at the output terminal. A sampling circuit makes measurements of an electrical characteristic of the voltage regulator at discrete moments of time, such as just before the opening and closing of the switch. A feedback circuit is coupled to the sampling circuit and the switch, and is configured to use the measurements to control the duty cycle to maintain the DC voltage substantially constant. The feedback circuit uses the switch as the resistive element in order to measure the current passing through the voltage regulator.

Abstract: In voltage regulator with a power switch to alternately couple and decouple an input voltage source to an output terminal at a switching frequency, a current supply provides a current that is proportional to the input voltage, the capacitance of a ramp capacitor, and a switching frequency. To provide this current, a first capacitor is charged to a first voltage, the first capacitor is discharged to a second voltage through a variable current source at a rate which is controlled by a third voltage on a second capacitor, the first capacitor is connected to the second capacitor to bring the second capacitor to a fourth voltage to adjust the rate of flow of charge through the variable current source, and the first capacitor is recharged to the first voltage. The rate of flow of charge through the variable current source controls the supply of current to the application.