A source follower with an input node and an output node includes a first transistor, a second transistor, and a DC (Direct Current) tracking circuit. The first transistor has a control terminal, a first terminal coupled to a first node, and a second terminal coupled to a second node. The second transistor has a control terminal, a first terminal coupled to a ground voltage, and a second terminal coupled to the first node. The DC tracking circuit sets the second DC voltage at the second node to a specific level. The specific level is determined according to the first DC voltage at the first node. The output node of the source follower is coupled to the first node.

A power supply system comprises an amplifier stage that includes at least one transistor, for example an LDMOS transistor. The transistor is connected to a supply voltage via a power connection, and is controlled by a control voltage at the control connection of the transistor. In some implementations, a first controller is provided for adjusting the control voltage of the transistor, and a second controller is provided for adjusting the supply voltage. In some implementations, one of the controllers is designed to feed a state signal to the other controller, and the other controller is designed to evaluate the state signal.

A power supply system comprises an amplifier stage that includes at least one transistor, for example an LDMOS transistor. The transistor is connected to a supply voltage via a power connection, and is controlled by a control voltage at the control connection of the transistor. In some implementations, a first controller is provided for adjusting the control voltage of the transistor, and a second controller is provided for adjusting the supply voltage. In some implementations, one of the controllers is designed to feed a state signal to the other controller, and the other controller is designed to evaluate the state signal.

An offset drift compensation circuit for correcting offset drift that changes with temperature. In one example, offset drift compensation circuit includes a low temperature offset compensation circuit and a high temperature offset circuit. The low temperature offset compensation circuit is configured to compensate for drift in offset at a first rate below a selected temperature. The high temperature offset compensation circuit is configured to compensate for drift in offset at a second rate above the selected temperature. The first rate is different from the second rate.

A common gate amplifier circuit configured to provide decreased voltage transients in the input voltage due to reverse gain. A second FET transistor is connected in series with a first FET of the common gate amplifier to function as an additional capacitive voltage divider between the amplifier output and the amplifier input without influencing the input or output currents. The first FET transistor, coupled to the amplifier input, may be a low voltage FET and smaller than the second FET transistor, which is coupled to the amplifier output. Both FET transistors are preferably enhancement mode GaN FET transistors and may be integrated into a single semiconductor chip with a single internal bias voltage divider.

Sense mirror circuitry receives a voltage signal having values corresponding to a magnitude of a measured current. Responsive to the values falling within a first predefined range, the sense mirror circuitry outputs a current at a first predefined magnitude that corresponds to the first predefined range. Responsive to the values falling within a second predefined range, the sense mirror circuitry outputs a current at a second predefined magnitude different than the first predefined magnitude and that corresponds to the second predefined range.

Sense mirror circuitry receives a voltage signal having values corresponding to a magnitude of a measured current. Responsive to the values falling within a first predefined range, the sense mirror circuitry outputs a current at a first predefined magnitude that corresponds to the first predefined range. Responsive to the values falling within a second predefined range, the sense mirror circuitry outputs a current at a second predefined magnitude different than the first predefined magnitude and that corresponds to the second predefined range.

Disclosed are a gyroscope and a charging device. The gyroscope includes: a casing, a motor, a circuit board and at least two tilt switches. The casing is provided with a rotation axis, the motor is fixedly mounted on the casing, an output shaft of the motor is coaxial with the rotation axis, an end of the output shaft away from the motor is located outside the casing, and the casing is rotatable around the rotation axis with the end of the output shaft away from the motor as a fulcrum. The circuit board is provided with a power supply and a current amplification circuit, the motor is connected to the power supply through the current amplification circuit. The at least two tilt switches are connected in series to the current amplification circuit for jointly controlling an on/off of the current amplification circuit.

Disclosed are a gyroscope and a charging device. The gyroscope includes: a casing, a motor, a circuit board and at least two tilt switches. The casing is provided with a rotation axis, the motor is fixedly mounted on the casing, an output shaft of the motor is coaxial with the rotation axis, an end of the output shaft away from the motor is located outside the casing, and the casing is rotatable around the rotation axis with the end of the output shaft away from the motor as a fulcrum. The circuit board is provided with a power supply and a current amplification circuit, the motor is connected to the power supply through the current amplification circuit. The at least two tilt switches are connected in series to the current amplification circuit for jointly controlling an on/off of the current amplification circuit.

In described examples, a circuit includes a first current mirror circuit. The first current mirror circuit is coupled to a power input terminal. A first stage is coupled to the first current mirror circuit, and a second stage is coupled to the first stage and to the first current mirror circuit. An amplifier is coupled to the first and second stages. The amplifier has first and second input terminals. The first input terminal is coupled to the first stage, and the second input terminal is coupled to the second stage. A second current mirror circuit is coupled to the first stage, the second stage and the amplifier.