Patent application number | Description | Published |
20090153254 | PHASE LOCKED LOOP CIRCUIT PERFORMING TWO POINT MODULATION AND GAIN CALIBRATION METHOD THEREOF - A PLL circuit for two point modulation includes a first loop filter, a second loop filter, a plurality of switching devices, and a calibration module. The first loop filter filters an output voltage of a charge pump during a gain calibration operation. The second loop filter filters the output voltage of the charge pump during a normal operation. The first loop filter has a bandwidth wider than that of the second loop filter to perform a fast calibration by reducing a lock time. The operation of the first loop filter, the operation of the second loop filter, and the opening of the first loop filter are determined by the switching operations of the switching devices. The calibration module adjusts a gain of analog modulation data based on a frequency error accumulated in the first loop filter after the first loop filter is open during the gain calibration operation. | 06-18-2009 |
20090185639 | DC OFFSET CORRECTION CIRCUIT FOR CANCELING A DC OFFSET IN REAL TIME AND A RECEIVING SYSTEM HAVING THE SAME - A DC offset correction circuit includes a DC offset detector generating a detection voltage based on a result of a comparison of a first reference voltage and a voltage difference between signals input to the DC offset detector, a comparator comparing a second reference voltage and the detection voltage and a third reference voltage and the detection voltage and outputting first and second comparison signals, respectively, as a result of the comparisons, and an up/down counter performing an up or a down count operation in response to one of the first or second comparison signals and, as a result of the up or down count operation, outputting a signal that causes at least one control signal for canceling a DC offset in a signal input to a receiver to be generated. | 07-23-2009 |
20110291632 | Power Converters Including Zero-Current Detectors And Methods Of Power Conversion - A power converter includes a zero-current detector having an adjustable offset voltage. The power converter includes a power converting unit and a switch driving circuit. The power converting unit generates a DC output voltage based on a pull-up driving signal, a pull-down driving signal and a DC input voltage. The switch driving circuit generates a first detection voltage signal based on the DC output voltage. The switch driving circuit includes a zero-current detector configured to adjust an offset voltage based on the first detection voltage signal and generate a zero-current detecting signal based on the offset voltage. The offset voltage and the zero-current detecting signal are associated with a current in the power converting unit. The switch driving circuit also includes a pulse-frequency modulating circuit configured to perform a pulse-frequency modulation (PFM) to generate the pull-up driving signal and the pull-down driving signal based on the zero-current detecting signal | 12-01-2011 |
20110309815 | POWER CONVERTER AND METHOD OF POWER CONVERSION - A power converter includes a power converting unit and a driving circuit. The power converting unit generates a DC output voltage based on a pull up driving signal, a pull down driving signal, and a DC input voltage. The driving circuit compensates for an inductor peak current, and performs in a pulse-frequency-modulation (PFM) mode and a pulse-width-modulation (PWM) mode to generate the pull-up driving signal and the pull-down driving signal based on the DC output voltage and the compensated inductor peak current. The power converter performs a mode transition between the PFM and PWM modes at a uniform load current, even when a magnitude of the DC output voltage varies. | 12-22-2011 |
20120242313 | SWITCHING REGULATOR, METHOD OF OPERATING THE SWITCHING REGULATOR, AND ELECTRONIC DEVICES HAVING THE SWITCHING REGULATOR - The switching regulator includes a voltage-to-current converter to convert a noise voltage into a noise current and output the noise current; and a sawtooth generator to output a sawtooth voltage signal having a frequency that varies in response to the noise current output from the voltage-to-current converter. | 09-27-2012 |
20140191744 | SWITCHING REGULATOR AND COMPARATOR-BASED ZERO CURRENT DETECTION METHOD USED BY THE SWITCHING REGULATOR - Provided are a switching regulator and a comparator-based zero current detection method. The switching regulator comprises: a switch configured to connect to a switching node and control an inductor current flowing through the switching node; and a switch controller configured to control a turn-off time of the switch by detecting a change in a voltage of the switching node after the switch is turned off, wherein the switch controller comprises: a comparator configured to compare a first voltage applied to a first input terminal connected to the switching node with a second voltage applied to a second input terminal connected to a first terminal of the switch; and a control logic configured to receive a comparison signal of the comparator and control an offset of the comparator to adjust the turn-off time of the switch. | 07-10-2014 |
20140253073 | BI-DIRECTIONAL VOLTAGE POSITIONING CIRCUIT, VOLTAGE CONVERTER AND POWER SUPPLY DEVICE INCLUDING THE SAME - A bi-directional voltage positioning circuit includes a voltage to current converter, a current mirror circuit and a switch. The voltage to current converter converts a sensing voltage to a first current, and the sensing voltage is sensed based on a current flowing through an output coil connected between a switching node and an output node. The current mirror circuit mirrors the first current to generate a second current and a third current, the second current is N times greater than the first current, the third current is M times greater than the first current, and N and M are real numbers greater than zero. The switch provides a feedback node with one of the second current and third current in response to a switching control signal, and an output voltage of the output node is divided at the feedback node. | 09-11-2014 |
20150180338 | HYSTERETIC SWITCHING REGULATOR - A switching regulator includes a power converting unit and a switch driving unit. The power converting unit is configured to generate a direct current (DC) output voltage based on a switch driving signal and a DC input voltage. The switch driving unit is configured to generate a ripple voltage having information of an inductor current flowing through the power converting unit, add the ripple voltage to a reference voltage to generate a first voltage having a ripple, generate a feedback voltage based on the DC output voltage, compare the first voltage with the feedback voltage in a hysteresis mode to generate a comparison output, and generate the switch driving signal based on the comparison output. | 06-25-2015 |