Abstract: A clock generation circuit, comprising a first RC circuit, a first switch, a second RC circuit, a second switch, a comparator and a logic circuit. The first RC circuit comprises a first capacitor, coupled to a first predetermined voltage level and a second predetermined voltage level. The second RC circuit comprises a second capacitor, coupled to the first switch. The comparator comprises: a first input terminal, coupled to the second RC circuit and the second switch; a second input terminal, configured to receive a reference voltage level; and an output terminal, coupled to a control terminal of the first switch and a control terminal of the second switch. The logic circuit is coupled to the output terminal of the comparator, configured to generate a clock signal. In one embodiment, the clock generation circuit is applied to an image sensor.

Abstract: A lighting control method of an optical pointing device is provided. An electric current is applied to a light emitting element within a predetermined turned-on period of an image sampling cycle, so that the light emitting element generates a light beam projected on a work surface where the optical pointing device is placed. A surface image of the work surface is captured by an image sensor within the predetermined turned-on period of the image sampling cycle. The surface image is analyzed to obtain a brightness of the surface image within the image sampling cycle. A current value of the electric current applied to the light emitting element according to the brightness of the surface image is determined before a starting point of a next image sampling cycle, such that a brightness of another surface image captured during the next image sampling cycle is maintained within a predetermined range.

Abstract: An amplifying circuit, which can operate in one of a sample mode and a hold mode, comprising: an amplifier; a current providing circuit, configured to provide a first bias current to the amplifier in a power saving time interval when the amplifying circuit operates in the sample mode, and configured to provide a second bias current to the amplifier when the amplifying circuit operates in the hold mode; wherein the first bias current is smaller than the second bias current.

Abstract: Disclosed are a power on reset circuit, a power on reset method and an electric device using the same. In the power on reset circuit and method, a first voltage detecting circuit and a second voltage detecting circuit detect the voltage of a power supply and output a first voltage signal and a second voltage signal respectively. A logic circuit receives the first voltage signal and the second voltage signal to turn no or off the first voltage detecting circuit for detecting the voltage of the power supply. Specifically, merely when the voltage value of the power supply is less than a rising threshold voltage value of the first voltage detecting circuit or a falling threshold voltage value of the second voltage detecting circuit, the first voltage detecting circuit is turned on to detect the voltage value of the power supply.

Abstract: Disclosed are a power on reset circuit, a power on reset method and an electric device using the same. In the power on reset circuit and method, a first voltage detecting circuit and a second voltage detecting circuit detect the voltage of a power supply and output a first voltage signal and a second voltage signal respectively. A logic circuit receives the first voltage signal and the second voltage signal to turn no or off the first voltage detecting circuit for detecting the voltage of the power supply. Specifically, merely when the voltage value of the power supply is less than a rising threshold voltage value of the first voltage detecting circuit or a falling threshold voltage value of the second voltage detecting circuit, the first voltage detecting circuit is turned on to detect the voltage value of the power supply.

Abstract: The present invention discloses a voltage conversion apparatus and a power-ON reset (POR) circuit and a control method thereof. The voltage conversion apparatus includes: a conversion circuit, an input status detection circuit, an output status detection circuit, a status feedback circuit, and a POR circuit. The POR circuit generates a POR signal according to an input status signal, an output status signal, and a feedback signal, to indicate whether a POR procedure is completed. The POR circuit includes: a logic circuit, for generating a reset signal indicating whether both the input and output voltages are ready; and a delay circuit, for generating the POR signal by delaying a predetermined time period according to the reset signal and a feedback signal related to the POR signal.

Abstract: The present invention discloses a voltage conversion apparatus and a power-ON reset (POR) circuit and a control method thereof. The voltage conversion apparatus includes: a conversion circuit, an input status detection circuit, an output status detection circuit, a status feedback circuit, and a POR circuit. The POR circuit generates a POR signal according to an input status signal, an output status signal, and a feedback signal, to indicate whether a POR procedure is completed. The POR circuit includes: a logic circuit, for generating a reset signal indicating whether both the input and output voltages are ready; and a delay circuit, for generating the POR signal by delaying a predetermined time period according to the reset signal and a feedback signal related to the POR signal.

Abstract: The present disclosure provides a driving circuit, which includes a switch, a driver unit, a fault detection circuit, and a processor. The switch is coupled between a power terminal and an anode of a light emitting diode (LED) of a light source. The driver unit is coupled between a cathode of the LED and a ground for generating a driving current according to a control signal. The fault detection circuit operatively detects whether the cathode of the LED is shorted and generate a fault signal when detected that the cathode of the LED is shorted. The processor initiates a fault detection period, during which the processor turns off the switch and the driver unit causes the cathode of the LED to be floating while activates the fault detection circuit to detect whether the cathode of the LED is shorted.

Abstract: The present disclosure provides a driving circuit, which includes a switch, a driver unit, a fault detection circuit, and a processor. The switch is coupled between a power terminal and an anode of a light emitting diode (LED) of a light source. The driver unit is coupled between a cathode of the LED and a ground for generating a driving current according to a control signal. The fault detection circuit operatively detects whether the cathode of the LED is shorted and generate a fault signal when detected that the cathode of the LED is shorted. The processor initiates a fault detection period, during which the processor turns off the switch and the driver unit causes the cathode of the LED to be floating while activates the fault detection circuit to detect whether the cathode of the LED is shorted.

Abstract: An optical navigation sensor includes: a driving circuit and a charge pump. The driving circuit is employed for driving a light source externally connected to the optical navigation sensor. The charge pump is employed for intermittently performing an operation of providing a first supply voltage to the light source. When the driving circuit drives the light source, the charge pump does not perform the operation of providing the first supply voltage to the light source.

Abstract: An optical navigation sensor includes: a driving circuit and a charge pump. The driving circuit is employed for driving a light source externally connected to the optical navigation sensor. The charge pump is employed for intermittently performing an operation of providing a first supply voltage to the light source. When the driving circuit drives the light source, the charge pump does not perform the operation of providing the first supply voltage to the light source.

Abstract: A driver circuit for a Light Emitting Diode (LED) is disclosed. The driver circuit is capable of supporting a constant LED current circuit configuration as well as an external resistor-controlled LED current circuit configuration. By integrating both configurations into a single driver circuit, the either circuit configuration can be selected without requiring a different driver circuit.

Abstract: A driver circuit for a Light Emitting Diode (LED) is disclosed. The driver circuit is capable of supporting a constant LED current circuit configuration as well as an external resistor-controlled LED current circuit configuration. By integrating both configurations into a single driver circuit, the either circuit configuration can be selected without requiring a different driver circuit.