Abstract: A constant current charging device is configured to charge a device to be charged and includes: a reference current source configured to provide a reference current; a current mirror electrically coupled to the reference current source and configured to output a mirror current; a current adjusting unit electrically coupled to the current mirror and the device to be charged and configured to output a charging current according to the mirror current to charge the device to be charged; and a current compensation unit electrically coupled to the current mirror and the current adjusting unit and configured to adjust the charging current according to a reference voltage.

Abstract: An electronic wake-up device and a wake-up method thereof are provided. The electronic wake-up device includes: a power switch device, an electronic device, a gravity sensor, and a wake-up circuit. The wake-up circuit is coupled to the gravity sensor and the electronic device. The wake-up circuit is configured to generate an execution signal according to a sensing activation signal, and generate an electronic device control signal according to the execution signal and a gravity signal to wake up the electronic device.

Abstract: A constant current charging device is configured to charge a device to be charged and includes: a current regulating unit electrically coupled to the device to be charged and configured to provide a regulating current and a charging current according to a reference voltage; a current-to-voltage converting unit electrically coupled to the current regulating unit and configured to output a regulating voltage according to the regulating current; and a first operational amplifier electrically coupled to the current regulating unit, the current-to-voltage converting unit, and the device to be charged and configured to regulate the regulating current.

Abstract: A constant current charging device is configured to charge a device to be charged and includes: a reference current source configured to provide a reference current; a current mirror electrically coupled to the reference current source and configured to output a mirror current; a current adjusting unit electrically coupled to the current mirror and the device to be charged and configured to output a charging current according to the mirror current to charge the device to be charged; and a current compensation unit electrically coupled to the current mirror and the current adjusting unit and configured to adjust the charging current according to a reference voltage.

Abstract: A frequency detector is used for detecting a frequency difference of a signal to be tested from a first time point to a second time point. The frequency detector includes: an alternating current coupled capacitor configured to receive the signal to be tested; a rectifying circuit electrically connected to the alternating current coupled capacitor; an analog-to-digital converter electrically connected to the rectifying circuit; a control unit electrically connected to the analog-to-digital converter; and a counter electrically connected to the rectifying circuit and the control unit, wherein the control unit is configured to calculate the frequency difference of the signal to be tested from the first time point to the second time point according to outputs of the analog-to-digital converter and outputs of the counter.

Abstract: A circuit for touch sensing includes a driving unit, a self-capacitive sensor circuit, a mutual-capacitive sensor circuit and a control circuit. The driving is configured to generate a driving signal. The self-capacitive sensor circuit is configured to generate a self-capacitance sensing result. The mutual-capacitive sensor circuit is configured to receive the driving signal in order to generate a mutual-capacitance sensing result when the voltage of a node between the self-capacitive sensor circuit and the mutual-capacitive sensor circuit reaches a reference voltage. The control circuit receives and computes the self-capacitance sensing result and the mutual-capacitance sensing result in order to generate a sensing result. By utilizing the circuit for touch sensing of present disclosure, the accuracy and the efficiency of touch sensing can be enhanced.

Abstract: A sensing device comprises a charge pump, a MEMS sensor, a source follower and a PGA. The charge pump is configured to provide a pump voltage. The MEMS sensor is electrically connected to the charge pump and configured to generate an input voltage according to environment variations. The source follower is electrically connected to the MEMS sensor and configured to generate a followed reference voltage according to the pump voltage and to generate a followed input voltage according to the input voltage. The PGA has an input end of the PGA electrically connected to the source follower and is configured to generate two-ended differential output voltages outputted through a first output end and a second output end according to a difference between the followed reference voltage and the followed input voltage.

Abstract: A configurable amplifier module is disclosed. The configurable amplifier module includes a first amplifier having a non-inverting input, an inverting input, and a first output; a second amplifier having a non-inverting input, an inverting input, and a second output; a first resistor; a second resistor; a third resistor; a detecting unit connected to the second output of the second amplifier and configured to detect whether a current flows through the detecting unit; and a control unit connected to the second resistor and the detecting unit and configured to control the second resistor to be connected to the third resistor or a direct current signal.

Abstract: An active stylus pen comprises a touch component and a pressure sensing module. One end of the touch component is disposed at a nib part of the active stylus pen, wherein the touch component is configured to receive an external pressure. The pressure sensing module is connected to the touch component, wherein the pressure sensing module is configured to generate an oscillation signal, wherein the oscillation signal has a first frequency when the touch component receives the external pressure and the external pressure reaches a first threshold value, and wherein the oscillation signal is adjusted to have a second frequency when the touch component receives the external pressure and the external pressure does not reach the first threshold value; wherein a difference of the first frequency and the second frequency is larger than a second threshold value.

Abstract: An analog microphone and a control method thereof are disclosed. The analog microphone includes a sensor configured to sense an audio signal and convert the audio signal into an electrical signal; a charge pump configured to provide a bias voltage for the sensor to drive the sensor; a source follower configured to receive the electrical signal and convert the electrical signal into a source follower signal; a gain adjustable amplifier configured to receive the source follower signal, multiply the source follower signal by an amplifying factor, and output an amplified signal; and a detecting module configured to adaptively control the bias voltage of the charge pump and the amplified signal of the gain adjustable amplifier in response to the source follower signal of the source follower.

Abstract: A frequency detector is used for detecting a frequency difference of a signal to be tested from a first time point to a second time point. The frequency detector includes: an alternating current coupled capacitor configured to receive the signal to be tested; a rectifying circuit electrically connected to the alternating current coupled capacitor; an analog-to-digital converter electrically connected to the rectifying circuit; a control unit electrically connected to the analog-to-digital converter; and a counter electrically connected to the rectifying circuit and the control unit, wherein the control unit is configured to calculate the frequency difference of the signal to be tested from the first time point to the second time point according to outputs of the analog-to-digital converter and outputs of the counter.

Abstract: A sensing device includes a micro-electromechanical sensor, a source follower and an amplifier. The source follower includes a first output module including a first transistor and a second transistor. The micro-electromechanical sensor is configured to generate an input signal. A first terminal of the first transistor is configured to receive a first reference voltage. A second terminal and a control of the first transistor are electrically connected to the first output terminal and to a first current source respectively. A first terminal and a second terminal of the second transistor are electrically connected to the second terminal and the control terminal of the first transistor respectively. A control terminal of the second transistor is configured to receive the input signal. A first input terminal and a second input terminal of the amplifier are electrically connected to a first output terminal configured to receive a common-mode voltage respectively.

Abstract: A configurable amplifier module is disclosed. The configurable amplifier module includes a first amplifier having a non-inverting input, an inverting input, and a first output; a second amplifier having a non-inverting input, an inverting input, and a second output; a first resistor; a second resistor; a third resistor; a detecting unit connected to the second output of the second amplifier and configured to detect whether a current flows through the detecting unit; and a control unit connected to the second resistor and the detecting unit and configured to control the second resistor to be connected to the third resistor or a direct current signal.

Abstract: An analog microphone and a control method thereof are disclosed. The analog microphone includes a sensor configured to sense an audio signal and convert the audio signal into an electrical signal; a charge pump configured to provide a bias voltage for the sensor to drive the sensor; a source follower configured to receive the electrical signal and convert the electrical signal into a source follower signal; a gain adjustable amplifier configured to receive the source follower signal, multiply the source follower signal by an amplifying factor, and output an amplified signal; and a detecting module configured to adaptively control the bias voltage of the charge pump and the amplified signal of the gain adjustable amplifier in response to the source follower signal of the source follower.

Abstract: A circuit for touch sensing includes a driving unit, a self-capacitive sensor circuit, a mutual-capacitive sensor circuit and a control circuit. The driving is configured to generate a driving signal. The self-capacitive sensor circuit is configured to generate a self-capacitance sensing result. The mutual-capacitive sensor circuit is configured to receive the driving signal in order to generate a mutual-capacitance sensing result when the voltage of a node between the self-capacitive sensor circuit and the mutual-capacitive sensor circuit reaches a reference voltage. The control circuit receives and computes the self-capacitance sensing result and the mutual-capacitance sensing result in order to generate a sensing result. By utilizing the circuit for touch sensing of present disclosure, the accuracy and the efficiency of touch sensing can be enhanced.

Abstract: A sensing device includes a MEMS sensor and an adjustable amplifier. The MEMS sensor is configured to generate an input signal according to environmental changes. The adjustable amplifier has a first input terminal, a second input terminal, a third input terminal, a fourth input terminal and a first output terminal. The first input terminal is electrically connected to the MEMS sensor for receiving the input signal. The second input terminal is electrically connected to a first signal terminal for receiving a first common-mode signal. The third input terminal is electrically connected to the first output terminal. The fourth input terminal is electrically connected to a second signal terminal. An electric potential of a first output signal output by the first output terminal of the adjustable amplifier is related to electric potentials of the input signal, the first signal terminal and the second signal terminal.

Abstract: A charge pump circuit includes N boosting circuits, (N?2) switching circuits and a control circuit. A kth boosting circuit includes a unidirectional component and a capacitor. A positive terminal of the unidirectional component of the kth boosting circuit is electrically connected to a negative terminal of a unidirectional component of a (k?1)th boosting circuit. A first terminal of the capacitor of the kth boosting circuit is electrically connected to a negative terminal of the unidirectional component of the kth boosting circuit. A (2i?1)th switching circuit selectively conducts a current path from a (2i?1)th boosting circuit to a first clock terminal or to a ground terminal according to a control signal of the control circuit. A (2i)th switching circuit selectively conducts a current path from a (2i)th boosting circuit to a second clock terminal or to the ground terminal according to the control signal of the control circuit.

Abstract: A source follower includes a first transistor, a first output module, a second transistor, a second output module and a feedback module. The first terminal and the control terminal of the first transistor are configured to respectively receive a first base voltage and a first control voltage. The second terminal of the first transistor and the first output module are electrically connected to a first output terminal. The first terminal and the control terminal of the second transistor are configured to respectively receive a first base voltage and a second control voltage. The second terminal of the second transistor and the second output module are electrically connected to a second output terminal. The feedback module is electrically connected to the control terminal of the first transistor, the control terminal of the second transistor and a reference node of the second output module.

Abstract: A programmable gain amplifier includes an active load module, a first differential pair, a second differential pair and a power source module. The first and second differential pairs are electrically connected to the active load module. The power source module is electrically connected to the first current source end of the first differential pair and the second current source end of the second differential pair. The power source module supplies a first current to the first differential pair through the first current source end. The power source module supplies a second current to the second differential pair through the second current source end. The power source module adjusts the potential of the first current, the potential of the second current, or both.

Abstract: An active stylus pen comprises a touch component and a pressure sensing module. One end of the touch component is disposed at a nib part of the active stylus pen, wherein the touch component is configured to receive an external pressure. The pressure sensing module is connected to the touch component, wherein the pressure sensing module is configured to generate an oscillation signal, wherein the oscillation signal has a first frequency when the touch component receives the external pressure and the external pressure reaches a first threshold value, and wherein the oscillation signal is adjusted to have a second frequency when the touch component receives the external pressure and the external pressure does not reach the first threshold value; wherein a difference of the first frequency and the second frequency is larger than a second threshold value.