A wireless power transmitter includes: a current adjuster configured to convert an input power into a transmission current, which is periodically varied according to a transmission frequency; and a power transmitter configured to receive the transmission current and wirelessly transmit power according to the transmission frequency.

A circuit includes an input for receiving power from an external power supply, a voltage regulator coupled to the power input and providing regulated voltage to an external circuit and to the power supply control circuit itself, and a first switch coupled between ground and an Enable input of the voltage regulator. A control input of the first switch is coupled to the regulated voltage, such that when the voltage regulator provides regulated voltage, the first switch is closed, coupling the Enable input to ground, keeping the voltage regulator active. A first switching circuit provides manual activation and deactivation of the voltage regulator; a second switching circuit provides automatic activation of the voltage regulator whenever the power input becomes powered. An intervening circuit prevents the second switching circuit from activating the voltage regulator when the first switching circuit has deactivated it, despite the continued presence of the external power supply.

A circuit includes an input for receiving power from an external power supply, a voltage regulator coupled to the power input and providing regulated voltage to an external circuit and to the power supply control circuit itself, and a first switch coupled between ground and an Enable input of the voltage regulator. A control input of the first switch is coupled to the regulated voltage, such that when the voltage regulator provides regulated voltage, the first switch is closed, coupling the Enable input to ground, keeping the voltage regulator active. A first switching circuit provides manual activation and deactivation of the voltage regulator; a second switching circuit provides automatic activation of the voltage regulator whenever the power input becomes powered. An intervening circuit prevents the second switching circuit from activating the voltage regulator when the first switching circuit has deactivated it, despite the continued presence of the external power supply.

Provided is a Precision Voltage Reference (PVR). In one example, the PVR includes a resonator having an oscillation frequency, the resonator including a first proof-mass, a first forcer located adjacent a first side of the first proof-mass, and a second forcer located adjacent a second side of the first proof-mass. The PVR may include control circuitry configured to generate a reference voltage based on the oscillation frequency of the resonator, at least one converter configured to receive the reference voltage from the control circuitry, provide a first bias voltage to the first forcer based on the reference voltage, provide a second bias voltage to the second forcer based on the reference voltage, and periodically alter a polarity of the first and second bias voltages to drive the oscillation frequency to match a reference frequency, and an output configured to provide the reference voltage as a voltage reference signal.

Provided is a Precision Voltage Reference (PVR). In one example, the PVR includes a resonator having an oscillation frequency, the resonator including a first proof-mass, a first forcer located adjacent a first side of the first proof-mass, and a second forcer located adjacent a second side of the first proof-mass. The PVR may include control circuitry configured to generate a reference voltage based on the oscillation frequency of the resonator, at least one converter configured to receive the reference voltage from the control circuitry, provide a first bias voltage to the first forcer based on the reference voltage, provide a second bias voltage to the second forcer based on the reference voltage, and periodically alter a polarity of the first and second bias voltages to drive the oscillation frequency to match a reference frequency, and an output configured to provide the reference voltage as a voltage reference signal.

Provided is a Precision Voltage Reference (PVR). In one example, the PVR includes a resonator having an oscillation frequency, the resonator including a first proof-mass, a first forcer located adjacent a first side of the first proof-mass, and a second forcer located adjacent a second side of the first proof-mass. The PVR may include control circuitry configured to generate a reference voltage based on the oscillation frequency of the resonator, at least one converter configured to receive the reference voltage from the control circuitry, provide a first bias voltage to the first forcer based on the reference voltage, provide a second bias voltage to the second forcer based on the reference voltage, and periodically alter a polarity of the first and second bias voltages to drive the oscillation frequency to match a reference frequency, and an output configured to provide the reference voltage as a voltage reference signal.

Provided is a Precision Voltage Reference (PVR). In one example, the PVR includes a resonator having an oscillation frequency, the resonator including a first proof-mass, a first forcer located adjacent a first side of the first proof-mass, and a second forcer located adjacent a second side of the first proof-mass. The PVR may include control circuitry configured to generate a reference voltage based on the oscillation frequency of the resonator, at least one converter configured to receive the reference voltage from the control circuitry, provide a first bias voltage to the first forcer based on the reference voltage, provide a second bias voltage to the second forcer based on the reference voltage, and periodically alter a polarity of the first and second bias voltages to drive the oscillation frequency to match a reference frequency, and an output configured to provide the reference voltage as a voltage reference signal.

The disclosure discloses a current balance circuit, which comprises a current sensing unit, a reference unit and an adjusting unit. The current sensing unit is configured to receive a plurality of input currents flowing through a plurality of channels having different impedances, and generate a plurality of corresponding input voltages according to the plurality of input currents. The reference unit is coupled to the current sensing unit, and configured to distribute a plurality of setting voltages corresponding to a plurality of output ends according to an output current ratio related to the plurality of output ends and the plurality of input voltages. The adjusting unit is coupled to the current sensing unit and the reference unit, and configured to adjust the plurality of input currents according to the plurality of setting voltages and input voltages, and generate a plurality of output currents to prevent a channel from being overloaded.

A circuit is provided that includes a first transistor having a first terminal, a second terminal and a third terminal, and a second transistor comprising a first terminal, a second terminal and a third terminal. The first terminal of the first transistor comprises an input terminal of the circuit, the second terminal of the first transistor is coupled to a power supply bus, and the first transistor conducts a first current. The first terminal of the first transistor comprises an output terminal of the circuit, the second terminal of the second transistor is coupled to the power supply bus, and the third terminal of the second transistor is coupled to the third terminal of the first transistor. The second transistor conducts a second current proportional to the first current substantially independent of distance between the first transistor and the second transistor.

A power supply efficiently suppresses transient voltages by storing the maximum charge expected in the transient and releasing it during the transient event at a rate in an equal but opposite amount to the transient, preventing the battery voltage from collapsing. The described power supply provides improved efficiency compared to conventional architectures for transient suppression, thus increasing the length of time between battery charges and creating a better user experience.