ADVANCED ANALOG TECHNOLOGY, INC. Patent applications |
Patent application number | Title | Published |
20120153859 | DRIVING CIRCUIT FOR DRIVING LIGHT EMITTING DIODES AND SIGNAL-EXTENDING CIRCUIT APPLIED TO A DRIVING CIRCUIT FOR DRIVING LIGHT EMITTING DIODES - A driving circuit for driving light emitting diodes includes a signal-extending circuit and a current sink. The signal-extending circuit is used for receiving an original dimming signal and extending a duty cycle of the original dimming signal. The current sink is coupled to the signal-extending circuit for generating a driving current for driving a series of light emitting diode. | 06-21-2012 |
20100039815 | LED APPARATUS AND THE PCB THEREOF - An LED apparatus comprises a PCB and a plurality of LEDs packaged on the PCB. The PCB materials on the area between the plurality of LEDs are partially removed to form a plurality of gaps, wherein the gaps are immediately close to the LEDs and directly dissipate heat of the LEDs. | 02-18-2010 |
20100026266 | PULSE WIDTH MODULATION CONTROLLER, CIRCUIT AND METHOD THEREOF WITH SHORT CIRCUIT PROTECTION - A PWM comprises a voltage transformation module, a voltage-sensing module and a timer. The voltage transformation module is configured to transform an input voltage into an output voltage. The voltage-sensing module is coupled to the voltage transformation module and configured to detect a voltage of a first terminal, wherein the voltage of the first terminal is proportional to the output voltage. The timer is configured to measure the time duration for which the voltage of the first terminal is lower than a reference voltage, wherein the timer initiates a short circuit signal when the time duration is greater than a predetermined value. | 02-04-2010 |
20100026254 | LOW DROPOUT REGULATOR AND THE OVER CURRENT PROTECTION CIRCUIT THEREOF - An over current protection circuit for low dropout regulator comprises a sense transistor, a sense resistor, an operational amplifier and a first transistor. The sense transistor senses the current flowing through the power transistor. The sense resistor is coupled to the sense transistor and shares the same current flowing through the sense transistor. The operational amplifier outputs a control signal according to the voltage across the sense resistor and a reference voltage. The first transistor controls the power transistor according to the control signal. | 02-04-2010 |
20100019747 | LOW DROPOUT REGULATOR - A low dropout regulator comprises a depletion mode NMOS transistor, a switch and an error amplifier. The source electrode of the depletion type NMOS transistor is coupled to a feedback circuit. The switch, controlled by a control signal, connects a supply voltage to the drain electrode of the depletion mode NMOS transistor. The non-inverting input terminal of the error amplifier is coupled to a reference voltage. The output terminal of the error amplifier is coupled to the gate electrode of the depletion mode NMOS transistor. The inverting input terminal of the error amplifier is coupled to the feedback circuit. | 01-28-2010 |
20090295305 | LED DRIVER CIRCUIT - An LED driver circuit comprises a buck-boost converter circuit and a resistor. The cathode terminal of the LED is connected to the output terminal of the buck-boost converter circuit. The anode terminal of the LED is connected to a reference voltage. The resistor connects the anode terminal of the LED to a power input. | 12-03-2009 |
20090289671 | FREQUENCY DIVIDER CIRCUIT - A frequency divider circuit comprises a plurality of T flip-flops, a first transmission gate, a second transmission gate and an inverter. The plurality of T flip-flops is connected in series. The output of the inverter is connected to a clock input of a first T flip-flop. The first transmission gate connects a clock signal and the other clock input of the first T flip-flop and the input of the inverter. The second transmission gate connects the inverted signal of the clock signal and the output of the first transmission gate. | 11-26-2009 |
20090273874 | POWER SWITCH CIRCUIT EXHIBITING OVER CURRENT AND SHORT CIRCUIT PROTECTION AND METHOD FOR LIMITING THE OUTPUT CURRENT THEREOF - A power switch circuit exhibiting over current and short circuit protections comprises a power-driving unit, a sense unit and a feedback controller circuit. The power-driving unit provides power to a load circuit from a power supply. The sense unit senses the output current of the power-driving unit. The feedback controller circuit controls the power-driving unit and the sense unit. When the output current of the power-driving unit exceeds a threshold, the output current is limited to an over current protection current level. When the resistance of the load circuit is approximately zero, the output current of the power-driving unit is limited to a short circuit protection current level. | 11-05-2009 |
20090261904 | MULTI-INPUT OPERATIONAL AMPLIFIER AND METHOD FOR REDUCING INPUT OFFSET THEREOF - A multi-input operational amplifier comprises two transconductors, two current mirrors, and a current source. Each transconductor generates a current according to a corresponding voltage difference. When the voltage difference is less than or equal to zero, the current is a constant. When the voltage difference exceeds zero, the current is proportional to the voltage difference. | 10-22-2009 |
20090206815 | SLOPE RATE COMPENSATION CIRCUIT, METHOD THEREOF AND PULSE WIDTH MODULATION BOOST CONVERTER CIRCUIT - A slope rate compensation circuit includes a source follower level-shift amplifier, a capacitor, a first resistor and a second resistor. The source follower level-shift amplifier includes a first transistor and a second transistor. The first transistor allows a first current to flow therein, the second transistor allows a second current to flow therein, and the first current increases with the second current. The capacitor is connected to the source terminal of the first transistor. The first resistor is connected to the source terminal of the second transistor. The second resistor allows a third current to flow therein, and the third current increases with the second current. The second resistor is related to the output voltage of the slope rate compensation circuit. | 08-20-2009 |
20090189661 | PULSE WIDTH MODULATION CONTROLLER AND THE CONTROLLING METHOD THEREOF - A pulse width modulation controller comprises a disabling unit, a level sensor and an over current protector. These three devices are all coupled to a multi-function node for accomplishing a disable function, input level sensing, and over-current protection, respectively. | 07-30-2009 |
20090189585 | PULSE WIDTH MODULATION CONTROLLER AND THE CONTROLLING METHOD THEREOF - A PWM controller for controlling a switching voltage regulator comprises a first comparator, a second comparator and a third comparator. The first comparator is configured to detect voltages of a first node and a second node so as to determine whether to stop the PWM controller. The PWM controller is stopped if a first potential is lower than a threshold, and the first potential derives from the voltage of the first node by a level shift of a first voltage difference. The second comparator is configured to detect the voltage of the first node and then to compare the voltage with a power reference voltage so as to determine whether the PWM controller receives necessary power. The third comparator is configured to compare the voltage of the second node with an enable reference voltage so as to determine whether to disable the PWN controller. | 07-30-2009 |
20090184701 | SWITCHING VOLTAGE REGULATOR, CONTROL CIRCUIT AND METHOD THEREOF - A control circuit comprises a PWM control circuit and a PWM skip control circuit. The PWM control circuit controls a switching circuit. The switching circuit acts as a current source for an output circuit and a load circuit. The PWM skip control circuit controls the operation of the PWM control circuit. When the output current of the switching circuit is below a predetermined threshold, the PWM skip control circuit stops the operation of the PWM control circuit. When the output voltage of the switching circuit is below a predetermined threshold, the PWM skip control circuit resumes the operation of the PWM control circuit. | 07-23-2009 |
20090174373 | CLAMP CIRCUIT AND COMBINATIONAL CIRCUIT THEREOF - A clamp circuit comprises a first transistor, a second transistor and a voltage-dividing circuit. The first transistor has a source terminal connected to a reference voltage, and has a drain terminal grounded through a current source. The second transistor has a gate terminal connected to the gate and drain terminals of the first transistor, and has a drain terminal grounded. The voltage-dividing circuit is connected to an input voltage end, an output voltage end and a source terminal of the second transistor for providing a clamping voltage. | 07-09-2009 |
20090167274 | PWM CONTROLLER AND THE CHIP THEREOF - A PWM controller applied to a switching voltage regulator comprises a disabling circuit, a power-sensing circuit, an over-current protection circuit and a PWM logic circuit. The disabling circuit is connected to an external frequency compensation circuit for detecting a voltage used to stop the operation of the PWM controller. The power-sensing circuit is configured to stop the operation of the PWM controller if the input voltage of the high side switch is lower than a threshold. The over-current protection circuit is configured to monitor current flowing through the output circuit, and the over-current protection circuit generates an over-current protection signal when the current exceeds a threshold. The PWM logic circuit is connected to the outputs of the disabling circuit, power-sensing circuit and over-current protection circuit. | 07-02-2009 |
20080315307 | HIGH VOLTAGE DEVICE - A high voltage device includes a semiconductor substrate and a gate. The semiconductor substrate includes a first doped region having a first conductive type, a second doped region having a second conductive type, a third doped region having the second conductive type, a fourth doped region surrounding the third doped region and having the second conductive type, and a fifth doped region surrounding the third doped region and having the second conductive type. The gate is disposed between two spacers to separate the second doped region from the third doped region, so as to control the conduction of the second doped region and the third doped region. In the high voltage device, the fifth doped region surrounds the third doped region, so as to strengthen the coverage for the third doped region and improve the ion concentration uniformity on the bottom of the third doped region to reduce leakage current. | 12-25-2008 |
20080231386 | Oscillation circuit and the method for using the same - The oscillation circuit includes an output current mirror, a P-N complementary current mirror, a P-type current mirror and an N-type current mirror. The P-N complementary current mirror has the same structure as the output current mirror but has current that is only 1/k times the current of the output current mirror, wherein k is greater than 1. The P-type current mirror connects to the P-N complementary current mirror, and has current that is m times the current of the P-N complementary current mirror, where m is greater than 1. The N-type current mirror has one end connected to the P-type current mirror and another end connected to the output current mirror. The N-type current mirror has current that is n times the current of the P-type current mirror, where | 09-25-2008 |
20080231348 | Circuit for fixing peak current of an inductor and method thereof - The circuit for fixing the peak current of an inductor includes an operating current, a ramp-type boost converter and a comparator. The magnitude of the operating current is proportional to that of the voltage source of the inductor. The ramp-type boost converter is connected to the operating current. One input end of the comparator is connected to a reference voltage, and the other end is connected to the output of the ramp-type boost converter. The output of the comparator is connected to the gate of a power transistor, which controls the turn-on time of the inductor. | 09-25-2008 |
20080225034 | Image sticking erasing circuit and method for using the same - The image sticking erasing circuit includes a detection circuit and a switching circuit connected to the detection circuit. The detection circuit is for use in detecting a first voltage signal, which closely follows the variation of the voltage source, and a reference voltage, which loosely follows the variation of the voltage source. When the detection circuit determines that the first voltage signal is lower than a first threshold value, the switching circuit switches the gate of a driving transistor to a second voltage signal, which loosely follows the voltage source. When the detection circuit determines that the reference voltage signal is lower than a second threshold value, the switching circuit switches the gate of a driving transistor to a low voltage state. | 09-18-2008 |
20080224673 | Circuit for starting up a synchronous step-up DC/DC converter and the method thereof - The low voltage circuit for starting up a synchronous step-up DC/DC converter, which connects to a voltage source through an inductor, includes a P-type power transistor, an N-type power transistor and a controller. The P-type power transistor includes a body diode, and one end of the P-type power transistor acts as a power source of an oscillator. The N-type power transistor connects the P-type power transistor in series, and both of the power transistors are not enabled at the same time. The oscillator electrically connects to the controller, which enables the P-type power transistor at initialization time, and enables the N-type power transistor a period after the initialization time. | 09-18-2008 |
20080221851 | Aid design system for analog integrated circuit and the method thereof - The aid design system for analog ICs includes an analog IC database, a peripheral component database, an input module, a computing simulation module, a selection module and an output module. The analog IC database includes parameters of a plurality of analog ICs. The peripheral component database includes parameters of the peripheral components cooperating with the analog ICs. The input module is for use in inputting a desirable parameter specification or specific IC according to the user's discretion. The computing simulation module includes transfer functions of the analog ICs. The selection module is for use in picking out suggested peripheral components based on the computing result of the computing simulation module. The output module is for use in displaying the suggested peripheral components or analog ICs. | 09-11-2008 |
20080218284 | Circuit and method for switching PFM and PWM - The switching method between pulse frequency modulation and pulse width modulation signals is first based on an output voltage of a power transistor to generate a corresponding pulse frequency modulation signal. Next, it is determined whether the corresponding pulse frequency modulation signal has reached its maximal frequency. If so, the initial pulse width modulation signal is adjusted to have the same width as the pulse frequency modulation signal. Thereafter, the adjusted pulse width modulation signal is outputted. | 09-11-2008 |
20080205099 | Power transistor circuit and the method thereof - The power transistor circuit with high-voltage endurance includes a first power transistor, a second power transistor and an enabling circuit. The first power transistor includes a first voltage endurance and a first inner resistance, while the second power transistor includes a second voltage endurance and a second inner resistance. The first voltage endurance and the first inner resistance are smaller than the second voltage endurance and the second inner resistance, respectively. The drain of the second power transistor is connected to the drain of the first power transistor and the enabling circuit. The enabling circuit enables the second power transistor first, and when the drain voltage of the first power transistor is smaller than the first endurance, the enabling circuit then enables the first power transistor. | 08-28-2008 |
20080197885 | Circuit for detecting maximal frequency of pulse frequency modulation and method thereof - The circuit for detecting the maximal frequency of the pulse frequency modulation includes an oscillator-controlling unit, a delay circuit and a master-slave register. The oscillator-controlling unit is connected to an oscillator, which generates the pulse frequency modulation signals, and includes a first-half pulse-generating module and a second-half pulse-generating module. The delay circuit is connected to the second-half pulse-generating module. The master-slave register includes a clock, an input end and an output end, wherein the input end is connected to the oscillator-controlling unit, and the clock is connected to the delay circuit. | 08-21-2008 |