Patent application number | Description | Published |
20080218221 | ANALOG SOURCE DRIVING APPARATUS - An analog source driving apparatus including an operational amplifier, a first resistor, a second resistor, a variable gain unit and a source driver is provided. A constant gain amplifier is composed with the operational amplifier, the first resistor, and the second resistor, wherein the first resistor is coupled between the inverse input terminal of the operational amplifier and the ground, and the second resistor is coupled between the inverse input terminal and the output terminal of the operational amplifier. The variable gain unit is coupled to an analog signal and the non-inverse input terminal of the operational amplifier for adjusting the analog signal to avoid affecting the zero point position and pole position of the system. Accordingly, the analog source driving apparatus can provide a stable driving output. | 09-11-2008 |
20080224768 | Operational Amplifier Capable of Compensating Offset Voltage - An operational amplifier capable of compensating offset voltage includes an input stage circuit having a positive input end, a negative input end, a first current output end, and a second current output end, for outputting current corresponding to voltage received by the positive and negative input ends, an output stage circuit coupled to the first current output end and the second current output end of the input stage circuit, for outputting voltage according to current outputted from the first current output end and the second current output end, and an trimming device coupled between the input stage circuit and the output stage circuit, for adjusting current of the first current output end or the second current output end for compensating offset voltage. | 09-18-2008 |
20080231347 | CHARGE PUMP CIRCUIT - A charge pump circuit including a plurality of switches and a switch control circuit is provided. The charge pump circuit is suitable for a display panel. The switches switch from “off” state to “on” state in an enable transition, and switch from “on” state to “off” state in a disable transition. The switch control circuit is coupled to the switches for controlling the on/off states of the switches and allowing the charge pump circuit to provide an output voltage that is different from an input voltage. The switch control circuit prolongs the time required for enable transition of the switches to be longer than the time for disable transition thereof. The equivalent impedances of the switches change from high values to low values when the switches are at the enable transition. | 09-25-2008 |
20080297125 | VOLTAGE REGULATOR, VOLTAGE REGULATING METHOD THEREOF AND VOLTAGE GENERATOR USING THE SAME - A voltage regulator and a voltage regulating method thereof and a voltage generator using the voltage regulator are disclosed by the present invention. The voltage regulator of the present invention uses a first switching unit and a second switching unit to respectively provide an operational transconductance amplifier (OTA) with different closed-loop feedback paths during a first period and a second period. In this way, an auto-zeroing unit is able to exactly store an input offset voltage presented between the inverting input terminal and the non-inverting input terminal of the OTA. | 12-04-2008 |
20090174466 | CHARGE PUMP CIRCUIT - A charge pump circuit is provided. The charge pump circuit includes a pump unit, first through sixth switches, a fly capacitor and an output capacitor. In a first period, an input voltage and a first voltage charge at least one internal capacitor of the pump unit via a first terminal and a second terminal of the pump unit. In the second period, the internal capacitor of the pump unit provides charges to the fly capacitor via the second switch and generates a first output voltage. In the third period, the fly capacitor supplies the charges to the output capacitor via the fourth switch to generate a second output voltage. | 07-09-2009 |
20090237046 | APPARATUS OF DYNAMIC FEEDBACK CONTROL CHARGE PUMP - An apparatus of dynamic feedback control charge pump is provided. The apparatus of dynamic feedback control charge pump receives an input voltage through a voltage regulator. The voltage regulator regulates the input voltage to a base voltage according to a control signal. The charge pump receives the base voltage and provides multiple of the base voltage to an output voltage. A feedback unit provides the control signal to the voltage regulator according to the output voltage. Therefore, the apparatus of dynamic feedback control charge pump can reduce the output voltage ripple and improve the output efficiency of the charge pump. | 09-24-2009 |
20090256626 | MULTI-STEP CHARGE PUMP AND METHOD FOR PRODUCING MULTI-STEP CHARGE PUMPING - A multi-step charge pump having a power input terminal and a power output terminal is provided. The multi-step charge pump includes a plurality of capacitors, wherein each of the capacitors has a capacitance. A plurality of switching devices is connected among the capacitors, the power input terminal and the power output terminal. A switch-controlling unit controls the on/off states of the switches, wherein a charging-phase circuit corresponding to a pumping level is formed to charge the capacitors and an output-phase circuit is formed to output a voltage from the power output terminal. At least one of the capacitors herein is changeably selected as a voltage-regulating capacitor. | 10-15-2009 |
20090289702 | CURRENT GENERATOR - A current generator, including a chopper stabilization operational amplifier, a transistor, and an impedance unit is provided. The chopper stabilization operational amplifier includes a first input terminal, a second input terminal, and an output terminal. The transistor includes a gate coupled to the output terminal of the chopper stabilization operational amplifier, a first source/drain coupled to the first input terminal of the chopper stabilization operational amplifier, and a second source/drain serving as a current output terminal of the current generator. The impedance unit includes a first terminal coupled to the first source/drain of the transistor, and a second terminal coupled to a first voltage. | 11-26-2009 |
20090315475 | LIGHT SOURCE APPARATUS AND LIGHT SOURCE ADJUSTING MODULE - A light source apparatus and a light source adjusting module are provided. The light source apparatus includes a power supply, a phase modulator, an electrical transformer, a light source adjusting module and a light-emitting device. The power supply provides a first AC voltage signal. The phase modulator receives the first AC voltage signal and adjusts a conducting phase of the first AC voltage signal to generate a modulated AC voltage signal. The electrical transformer transforms the modulated AC voltage signal to generate a second AC voltage signal. The light adjusting module generates a luminance adjusting signal according to a state of the second AC voltage signal. The light-emitting device receives the luminance adjusting signal to generate a corresponding light source. | 12-24-2009 |
20100033102 | Light Adjusting Device for a Light Emitting Diode and Related Light Adjusting Method and Light Emitting Device - A light adjusting device for a light emitting diode includes a switch, a detecting unit and an illumination adjusting unit. The switch is coupled to a power terminal, which is utilized for providing power for the light emitting diode. The detecting unit is coupled to the switch, and is utilized for determining a status of the switch, so as to generate a detecting result. The illumination adjusting unit is coupled to the detecting unit, and is utilized for adjusting illumination of the light emitting diode according to the detecting result. | 02-11-2010 |
20100039842 | POWER CONVERSION SYSTEM AND POWER CONVERSION METHOD THEREOF - A power conversion system and a power conversion method thereof. The power conversion system includes a driving unit, a control unit, a first direct current (DC) power supply circuit and a second DC power supply circuit. The control unit controls the driving unit to drive a load. The first DC power supply circuit converts an alternating current (AC) power into a first DC power outputted to the driving unit, and the second DC power supply circuit converts the AC power into a second DC power outputted to the control unit. | 02-18-2010 |
20100117618 | OVER CURRENT PROTECTION CIRCUIT AND POWER CONVERTER USING THE SAME - An over current protection circuit and a power converter using the same. The over current protection circuit includes a soft start cell and an operational amplifier. The soft start cell outputs a soft start signal according to a direct current (DC) level, and the soft start signal increases progressively to the DC level in a soft start interval. The operational amplifier outputs an over current signal to a feedback control circuit according to the soft start signal and an inductance current of a switching converter so that a duty cycle of a driving signal from the feedback control circuit increases progressively in the soft start interval. | 05-13-2010 |
20100117721 | GENERATOR AND METHOD FOR GENERATING REFERENCE VOLTAGE AND REFERENCE CURRENT - A generator for generating reference voltage and reference current includes a reference voltage generating circuit for generating a first voltage and a second voltage, which are in combination to produce a reference voltage. The first voltage and the second voltage are respectively having a first-direction response variation and a second-direction response variation, according to a temperature variation. A voltage-to-current inverting circuit is coupled to the reference voltage generating circuit for generating a first current, which has the first-direction response variation as the temperature variation, according to the first voltage. An adding circuit is coupled to the reference voltage generating circuit and the voltage-to-current inverting circuit to obtain a second current corresponding to the second voltage from the reference voltage generating circuit. The first current and the second current are added to have a reference current. The second current has the second-direction response variation as the temperature variation. | 05-13-2010 |
20100156309 | LED ILLUMINANT DRIVING CIRCUIT AND AUTOMATIC BRIGHTNESS COMPENSATION METHOD THEREOF - An LED illuminant driving circuit and an automatic brightness compensation method thereof are provided herein. The automatic brightness compensation method includes: providing a target value; detecting an operation period of a pulse of an output of the LED illuminant driving circuit, the pulse is adapted to an LED illuminant for making the light emitting; deciding a peak value according to the target value and the operation period; and setting a peak level of the pulse according to the peak value. The LED illuminant driving circuit and the automatic brightness compensation method thereof provides a stable average current/voltage to the LED illuminant and avoids brightness variations of the light emitting. | 06-24-2010 |
20120104963 | LIGHT SOURCE APPARATUS AND LIGHT SOURCE ADJUSTING MODULE - A light source apparatus and a light source adjusting module are provided. The light source apparatus includes a power supply, a phase modulator, an electrical transformer, a light source adjusting module and a light-emitting device. The power supply provides a first AC voltage signal. The phase modulator receives the first AC voltage signal and adjusts a conducting phase of the first AC voltage signal to generate a modulated AC voltage signal. The electrical transformer transforms the modulated AC voltage signal to generate a second AC voltage signal. The light adjusting module generates a luminance adjusting signal according to a state of the second AC voltage signal. The light-emitting device receives the luminance adjusting signal to generate a corresponding light source. | 05-03-2012 |