A voltage regulator circuit for RFID circuit utilizing a high efficiency circuit topology to minimize power consumption to provide only required current to regulate output voltage. The voltage regulator circuit does not consume quiescent current which minimizes power consumption. It does not contain inductor, transformer, op-amp, voltage and current reference which reduces complexity and die area. The voltage regulator circuit comprises a driving element, a control circuit and a sensing circuit. The driving element drives controlled current to output to ramp up the voltage. The sensing circuit measures voltage at the output and sends signal to the control circuit if the voltage reaches target value set by the internal parameters of the components. The control circuit stops the driving element when output voltage reaches the threshold minimizing current required to regulate voltage.

Techniques and apparatus for operating an always-on low-dropout (LDO) voltage regulator during cold boot and different sleep mode scenarios for a device including the LDO regulator. The LDO regulator may be disposed, for example, in a wireless local area network (WLAN) device powered by a coin cell battery. One example apparatus may be an integrated circuit (IC), which may be disposed in such a WLAN device and/or may be a power management unit (PMU). The IC generally includes a first port for coupling to a battery, a second port, a switched-mode power supply (SMPS) including a power supply input coupled to the second port, and an LDO regulator including a power supply input selectively coupled to the first port or to an output of the SMPS.

A power supply circuit and a chip to which the power supply circuit is applied are disclosed. The power supply circuit includes a constant current generation circuit and a voltage generation circuit. The constant current generation circuit is configured to generate a first current with a positive temperature coefficient and a second current with a negative temperature coefficient, and generate a constant current according to the first current and the second current. The voltage generation circuit includes a transistor, is coupled to the constant current generation circuit, and configured to generate a temperature-dependent voltage according to the constant current and characteristics of the transistor.

A power supply circuit and a chip to which the power supply circuit is applied are disclosed. The power supply circuit includes a constant current generation circuit and a voltage generation circuit. The constant current generation circuit is configured to generate a first current with a positive temperature coefficient and a second current with a negative temperature coefficient, and generate a constant current according to the first current and the second current. The voltage generation circuit includes a transistor, is coupled to the constant current generation circuit, and configured to generate a temperature-dependent voltage according to the constant current and characteristics of the transistor.

Devices for reducing the open circuit voltages of solar systems are described. In one embodiment, a solar system includes a string of a plurality of solar modules having an open circuit voltage. The solar system also includes a device for reducing the open circuit voltage of the string of the plurality of solar modules during an open circuit configuration.

Devices for reducing the open circuit voltages of solar systems are described. In one embodiment, a solar system includes a string of a plurality of solar modules having an open circuit voltage. The solar system also includes a device for reducing the open circuit voltage of the string of the plurality of solar modules during an open circuit configuration.

An apparatus for regulating a bias-voltage of a switching power supply is disclosed. The apparatus includes a cascode amplifier, feedback-circuit, and bias-regulator circuit. The cascode amplifier includes a common-gate transistor and common-source transistor, where a source of the common-gate transistor is in signal communication with a drain of the common-source transistor. The feedback-circuit is in signal communication with the source of the common-gate transistor and the drain of the common-source transistor and the bias-regulator circuit is in signal communication with a gate of the common-source transistor, a gate of the common-gate transistor, and the feedback-circuit. The feedback-circuit receives a drain-voltage from the drain of the common-source transistor and produces a feedback-voltage and the bias-regulator circuit is configured to receive the feedback-voltage and produce and regulate the bias-voltage. A gate-voltage is produced from the bias-voltage and the gate-voltage is injected into the gate of the common-gate transistor.

A synchronous rectifier alternator and a power allocation method thereof are provided. The synchronous rectifier alternator includes an alternator, a synchronous rectifier circuit and a controller. The alternator converts mechanical energy to alternating current (AC) electrical energy. The synchronous rectifier circuit converts the AC electrical energy to direct current (DC) electrical energy and provides the DC electrical energy to a load. The controller detects a voltage level of the DC electrical energy. When the controller detects that the voltage level is higher than or equal to a first threshold voltage value, the controller controls ONs and OFFs of first transistors and second transistors of the synchronous rectifier circuit, such that at least one of regulator diodes of the synchronous rectifier circuit, a stator of the alternator and the load consume power of the alternator.

A synchronous rectifier alternator and a power allocation method thereof are provided. The synchronous rectifier alternator includes an alternator, a synchronous rectifier circuit and a controller. The alternator converts mechanical energy to alternating current (AC) electrical energy. The synchronous rectifier circuit converts the AC electrical energy to direct current (DC) electrical energy and provides the DC electrical energy to a load. The controller detects a voltage level of the DC electrical energy. When the controller detects that the voltage level is higher than or equal to a first threshold voltage value, the controller controls ONs and OFFs of first transistors and second transistors of the synchronous rectifier circuit, such that at least one of regulator diodes of the synchronous rectifier circuit, a stator of the alternator and the load consume power of the alternator.

A low dropout voltage regulator for generating an output regulated voltage is provided. The low dropout voltage regulator includes a first transistor and a current recycling circuit. The first transistor has a first terminal for receiving an input supply voltage, a second terminal for generating the output regulated voltage, and a control terminal for receiving a control voltage. The current recycling circuit is configured to drain a feeding current to the second terminal of the first transistor in response to a first signal having feedback information of the output regulated voltage.