A voltage regulator is provided. The voltage regulator includes a shunt transistor and a feedback circuit. The shunt transistor has a first current electrode coupled to a first voltage source terminal, a second current electrode coupled to a second voltage source terminal, a control electrode coupled to receive a reference voltage, and a body electrode. The feedback circuit has an input terminal coupled to the body electrode of the shunt transistor, and an output terminal coupled to the control electrode of the shunt transistor. The voltage regulator is suitable for use in a passive RFID device to protect the device from over-voltage damage. In another embodiment, a method for regulating a voltage is provided.

A shunt regulator includes: a capacitor, connected between an output terminal and a ground terminal; a voltage divider circuit and an output transistor, connected between the output terminal and the ground terminal; an error amplifier, controlling the output transistor based on a voltage at an output terminal of the voltage divider circuit and a reference voltage; a non-volatile memory; a memory control circuit, outputting a data read signal to the non-volatile memory; and a voltage detection circuit, detecting that a voltage at the output terminal has reached a predetermined voltage which permits a data reading operation of the non-volatile memory, and outputting a detection signal to the memory control circuit. An operating current of the non-volatile memory is supplied from the capacitor.

A shunt regulator includes: a capacitor, connected between an output terminal and a ground terminal; a voltage divider circuit and an output transistor, connected between the output terminal and the ground terminal; an error amplifier, controlling the output transistor based on a voltage at an output terminal of the voltage divider circuit and a reference voltage; a non-volatile memory; a memory control circuit, outputting a data read signal to the non-volatile memory; and a voltage detection circuit, detecting that a voltage at the output terminal has reached a predetermined voltage which permits a data reading operation of the non-volatile memory, and outputting a detection signal to the memory control circuit. An operating current of the non-volatile memory is supplied from the capacitor.

An integrated circuit, such as included as a portion of a sensor node, can include a regulator circuit having an input coupleable to an energy harvesting transducer. The integrated circuit can include a wireless receiver circuit coupled to the regulator circuit and configured to wirelessly receive at least enough operating energy to establish operation of the sensor node without requiring the energy harvesting transducer. The integrated circuit can include a digital processor circuit coupled to the regulator circuit and a power management processor circuit. The digital processor circuit or one or more other circuits can include a subthreshold operational mode established by the power management processor circuit based on the selected energy consumption level. For example, establishing the subthreshold operational mode can include adjusting or selecting a supply voltage so as to establish subthreshold operation of a field effect transistor (FET) in the digital processor circuit or other circuits.

The present invention provides for a high voltage direct current power supply including a primary high voltage direct current supply offering a primary output; a floating secondary output floating with respect to the primary output and fed by the primary output: an output terminal at the floating secondary output for providing an output voltage; a controller operative to detect a change in the output voltage at the output terminal and to generate a control signal responsive to the change in output voltage; and a controllable current source, which can comprise a programmable current source, arranged to provide current at the floating secondary output responsive to the said control signal and whereby the said current is provided to reduce charging of a secondary output capacitance as the output voltage changes.

In a power supply device, a voltage controller includes: a reference voltage circuit that generates a reference voltage based on an input voltage; a voltage control circuit that generates ate output voltage of the voltage controller based on the input voltage by controlling an output current of the voltage controller so that the output voltage of the voltage controller corresponds to the reference voltage; and a first current detector circuit that detects the output current of the voltage controller, and generates a first current detection signal corresponding to the output current thereof. A current controller includes: a second current detector circuit that detects an output current of the current controller, and generates a second current detection signal corresponding to the output current thereof; and a current control circuit controls the output current of the current controller so that the second current detection signal corresponds to the first current detection signal.

A power supply includes a voltage converter to produce an output voltage to power a load. The power supply further includes a reference voltage generator and a controller. The reference voltage generator is operative to generate a floor reference voltage that varies as a function of the output voltage depending on a setting of one or more adjustable (programmable) resistor-capacitor paths in the floor reference voltage generator. The controller produces control signals to control the voltage converter as a function of the floor reference voltage and the output voltage.

A power supply includes a voltage converter to produce an output voltage to power a load. The power supply further includes a reference voltage generator and a controller. The reference voltage generator is operative to generate a floor reference voltage that varies as a function of the output voltage depending on a setting of one or more adjustable (programmable) resistor-capacitor paths in the floor reference voltage generator. The controller produces control signals to control the voltage converter as a function of the floor reference voltage and the output voltage.

A controller for a half-bridge power circuit includes a measurement circuit, a controller circuit, a high-side delay circuit, and a low-side delay circuit. The measurement circuit connects to the half-bridge node, measures the half-bridge voltage, and generates a multi-bit status signal indicative of the measured half-bridge voltage. The controller circuit connects to the measurement circuit, and receives the status signal therefrom. The controller circuit generates at least a delay control signal based on the status signal. The high-side delay circuit connects to the controller circuit to receive the delay control signal. The high-side delay circuit provides a high-side control signal in response to the delay control signal, to switch on/off the high-side switch. The low-side delay circuit connects to the controller circuit to receive the delay control signal. The low-side delay circuit provides a low-side control signal in response to the delay control signal, to switch on/off the low-side switch.

A controller for a half-bridge power circuit includes a measurement circuit, a controller circuit, a high-side delay circuit, and a low-side delay circuit. The measurement circuit connects to the half-bridge node, measures the half-bridge voltage, and generates a multi-bit status signal indicative of the measured half-bridge voltage. The controller circuit connects to the measurement circuit, and receives the status signal therefrom. The controller circuit generates at least a delay control signal based on the status signal. The high-side delay circuit connects to the controller circuit to receive the delay control signal. The high-side delay circuit provides a high-side control signal in response to the delay control signal, to switch on/off the high-side switch. The low-side delay circuit connects to the controller circuit to receive the delay control signal. The low-side delay circuit provides a low-side control signal in response to the delay control signal, to switch on/off the low-side switch.