In a circuit for DC-DC voltage converters, an amplifier has first and second inputs coupled to a reference voltage terminal and an output voltage terminal, respectively. A comparator has first and second inputs coupled to an amplifier output and a switching terminal, respectively. A logic circuit has inputs coupled to the comparator output and a clock terminal. A driver circuit has first and second inputs coupled to first and second logic outputs, respectively. A first transistor having a first control terminal coupled to the first driver output is coupled between a supply voltage terminal and the switching terminal. A second transistor is coupled between the switching terminal and a ground terminal, and has a second control terminal coupled to the second driver output. A threshold detection circuit is configured to provide a threshold signal responsive to a current through the second transistor crossing a current threshold.

In a circuit for DC-DC voltage converters, an amplifier has first and second inputs coupled to a reference voltage terminal and an output voltage terminal, respectively. A comparator has first and second inputs coupled to an amplifier output and a switching terminal, respectively. A logic circuit has inputs coupled to the comparator output and a clock terminal. A driver circuit has first and second inputs coupled to first and second logic outputs, respectively. A first transistor having a first control terminal coupled to the first driver output is coupled between a supply voltage terminal and the switching terminal. A second transistor is coupled between the switching terminal and a ground terminal, and has a second control terminal coupled to the second driver output. A threshold detection circuit is configured to provide a threshold signal responsive to a current through the second transistor crossing a current threshold.

In a circuit for DC-DC voltage converters, an amplifier has first and second inputs coupled to a reference voltage terminal and an output voltage terminal, respectively. A comparator has first and second inputs coupled to an amplifier output and a switching terminal, respectively. A logic circuit has inputs coupled to the comparator output and a clock terminal. A driver circuit has first and second inputs coupled to first and second logic outputs, respectively. A first transistor having a first control terminal coupled to the first driver output is coupled between a supply voltage terminal and the switching terminal. A second transistor is coupled between the switching terminal and a ground terminal, and has a second control terminal coupled to the second driver output. A threshold detection circuit is configured to provide a threshold signal responsive to a current through the second transistor crossing a current threshold.

The present invention relates generally to the field of electret capsule, and more particularly to a circuit configuration of an impedance converter integrated in an electret capsule such as for use in condenser microphones. The electret capsule of a microphone may include a gate biasing field effect transistor (FET) to facilitate biasing of a low noise FET. Advantageously, the use of low noise FET in the electret capsule of a microphone provides for a reduced cost, while achieving lower self-noise.

A cell includes a first pair and a second pair of MOS transistors. Each of the first pair and second pair of MOS transistors have drain electrodes coupled to a respective common input node. Each of the first pair and second pair of MOS transistors includes a diode-connected MOS transistor and a latched MOS transistor. The latched MOS transistors of the first pair and second pair of MOS transistors have cross-coupled gate and drain electrodes. Source electrodes of the diode connected MOS transistors from the first pair and second pair of MOS transistors are coupled to a first current output common node to output a current to a first current collecting circuit. Source electrodes of the latched MOS transistors of the first pair and second pair of MOS transistors are coupled to a second current output common node to output a current to a second current collecting circuit.

A linear power supply circuit includes an output transistor provided between an input terminal to which an input voltage is applied and an output terminal to which an output voltage is applied, and a driver configured to drive the output transistor based on the difference between a voltage based on the output voltage and a reference voltage. The driver includes a differential amplifier, a converter, and a first capacitor provided between the output of the differential amplifier and a ground potential. The linear power supply circuit further includes a source follower circuit including a first transistor, and moreover includes a second transistor connected in series with the output transistor and constituting together with the first transistor a current mirror circuit, and a second capacitor connected to the control terminal of the first transistor.

Proposed is a band gap reference circuit under a low supply voltage capable of generating a band gap reference voltage even under a low supply voltage by using a plurality of bias voltages separately generated and a current source using these bias voltages without using a diode connected structure used in the related art while not being affected by limitations in the operating voltage of a bipolar transistor. The band gap reference circuit under a low supply voltage includes a voltage reference main circuit configured to generate a first node voltage and a second node voltage in response to a first bias voltage and a band gap reference voltage, and a transimpedance amplifier configured to generate the band gap reference voltage by amplifying a difference between the first node voltage and the second node voltage using the first bias voltage, a second bias voltage, and a third bias voltage.

The present invention relates generally to the field of electret capsule circuit, and more particularly to a circuit configuration of an impedance converter integrated in an electret capsule such as for use in condenser microphones. The electret capsule of a microphone may include a gate biasing field effect transistor (FET) to facilitate biasing of a low noise FET. Advantageously, the use of low noise FET in the electret capsule of a microphone provides for a reduced cost, while achieving lower self-noise.

An amplifier circuit having low parasitic pole effect includes a preamplifier, an output transistor and a buffer circuit. The buffer circuit generates a driving signal to control the output transistor according to a preamplification signal generated by the preamplifier. The buffer circuit includes: a buffer input transistor generating the driving signal, wherein an input impedance at its control end is less than that of the output transistor; a low output impedance circuit having an output impedance which is less than an inverting output impedance of the buffer input transistor; an amplification transistor generating an amplification signal at its inverting output; and an amplification stage circuit amplifying the amplification signal by an amplification ratio, so that an equivalent output impedance at a non-inverting output of the buffer input transistor is less than or equal to a product of the reciprocal of an intrinsic output impedance thereof and an amplification ratio.

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.