| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 330297000 | Including particular power supply circuitry | 65 |
| 20130027138 | AMPLIFIER CIRCUIT AND METHOD FOR SIGNAL SENSING - An amplifier circuit ( | 01-31-2013 |
| 20130043953 | METHODS, CIRCUITS AND SYSTEMS FOR REGULATING THE OUTPUT POWER OF A TRANSMISSION SYSTEM - Disclosed are methods, circuits and systems for regulating the output power of a transmission system. There may be provided a power amplifier (“PA”) adapted to operate across a range of supply voltages. The PA may operate under different bias profiles. There may be provided power amplifier regulation circuitry which may include a PA bias profile generator adapted to generate one or more bias profiles, wherein a given bias profile is associated with a given bias signal for the PA. A bias profile associated with a given bias signal for a given PA may include one or more PA parameters or settings to be applied to the given PA when it is operating with the given bias signal. | 02-21-2013 |
| 20130033328 | EFFICIENT POWER AMPLIFIER - A dynamic power supply for N amplifiers includes first and second power boost circuits which temporarily boost the positive or negative power supply rail, respectively. A control circuit monitors amplifier output signal levels and provides power boost control signals to the power boost circuits, which temporarily raise the positive supply voltage above the nominal voltage level in tandem with the highest output signal from the N amplifiers and lower the negative supply voltage below the nominal voltage level in tandem with the lowest output signal level from the N amplifiers. The power boost circuits each may be coupled to a reservoir capacitor from which current is drawn to provide the power boost. When inactive, the reservoir capacitors charge up from the respective power supply rails. The dynamic power supply is well suited for audio amplification systems. | 02-07-2013 |
| 20090302950 | SINGLE INPUT DUAL OUTPUT VOLTAGE POWER SUPPLY AND METHOD THEREFOR - In one embodiment, a power supply controller is configured to form both positive and negative supply voltages from a single input voltage so the maximum differential voltage across a load that uses the positive and negative supply voltages is no greater than the maximum value of the input voltage | 12-10-2009 |
| 20130057351 | Current-Voltage Converter Having a Current Reflector, Input Stage of an Amplifier and Corresponding Amplifier - This current-voltage converter( | 03-07-2013 |
| 20090091394 | DEVICE TO GENERATE A MODULATED ELECTRICAL RADIO-FREQUENCY SIGNAL FOR A MAGNETIC RESONANCE APPLICATION - A device for generation a modulated electrical radio-frequency signal for a magnetic resonance application has a phase modulator that generates a phase-modulated radio-frequency base signal, an amplitude modulator that generates an amplitude-modulated supply voltage, and a non-linear transmission output stage that, to supply the radio-frequency base signal, is connected via a signal input with the phase modulator and, to feed in the supply voltage, is connected via a supply voltage input with the amplitude modulator. The amplitude modulator includes at least two switching power supplies connected in parallel and clocked phase-offset relative to one another. | 04-09-2009 |
| 20120223777 | RF Power Amplifier Circuit With Mismatch Tolerance - A radio frequency (RF) power amplifier system adjusts the supply voltage provided to a power amplifier (PA) adaptively, responsive to the measured or estimated power of the RF output signal of the PA. The RF PA system includes a power amplifier (PA) which receives and amplifies an RF input signal to generate an RF output signal at a level suitable for transmission to an antenna. A PA supply voltage controller generates a supply voltage control signal, which is used to control the supply voltage to the final stage of the PA. The supply voltage control signal is generated responsive to the measured or estimated power of the PA RF output signal, and also may be responsive to a parameter indicative of impedance mismatch experienced at the PA output. By controlling this supply voltage to the RF PA, the efficiency of the PA is improved. | 09-06-2012 |
| 20130063216 | POWER OFF DELAY CIRCUIT AND METHOD, AND AUDIO SYSTEM WITH POWER OFF DELAY - A power off delay circuit includes a switch connected between an external power input terminal and an internal power supply terminal, a capacitor connected to the internal power supply terminal, and a hysteresis comparator to switch the switch according to the voltages of the external power input terminal and the internal power supply terminal. During on-time of the switch, the external power input terminal is connected to the internal power supply terminal and the capacitor can be charged by the external power source. When the switch is off, the capacitor provides electric power for an internal circuit. Application of the power off delay circuit to an audio system may eliminate the turn-off pops of the audio system. | 03-14-2013 |
| 20110298546 | SATURATION PROTECTION OF A REGULATED VOLTAGE - A system for preventing power amplifier supply voltage saturation includes a multiple stage voltage regulator configured to provide a regulated voltage, a power amplifier configured to receive the regulated voltage, and a saturation protection circuit configured to apply a current into a first stage of the multiple stage voltage regulator when the regulated voltage reaches a reference voltage, the applied current causing a subsequent stage of the multiple stage voltage regulator to prevent the regulated voltage from exceeding the reference voltage. | 12-08-2011 |
| 20110285468 | Pre-amplifier - A pre-amplifier comprises at least two PMOS transistors operated as source followers and two NMOS transistors operated as amplifiers, or, two NMOS transistors operated as source followers and two PMOS transistors operated as amplifiers to raise or reduce the voltage of input signals and at least four current sources with the same current value which can be adjusted according to the output load of the pre-amplifier. The MOS transistors have the same transconductance so that the minimum differential voltage can be attained. Since the differential signals change alternately, MOS transistors will switch among the three working status: cut-off, saturation and linear region. Because of the cut-off and linear region, the present invention can achieve the very low power consumption less than one third of the conventional one. | 11-24-2011 |
| 20080211584 | Cross-differential amplifier - A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches. | 09-04-2008 |
| 20120098602 | POWER CONSUMPTION CONTROL CIRCUIT, AMPLIFIER CIRCUIT AND POWER CONSUMPTION CONTROL METHOD - Provided is a power consumption control circuit, an amplifier circuit and a power consumption control method which control the power consumption associated with an amplification action in real time. | 04-26-2012 |
| 20110032039 | EFFICIENT POWER AMPLIFIER - A dynamic power supply for N amplifiers includes first and second power boost circuits which temporarily boost the positive or negative power supply rail, respectively. A control circuit monitors amplifier output signal levels and provides power boost control signals to the power boost circuits, which temporarily raise the positive supply voltage above the nominal voltage level in tandem with the highest output signal from the N amplifiers and lower the negative supply voltage below the nominal voltage level in tandem with the lowest output signal level from the N amplifiers. The power boost circuits each may be coupled to a reservoir capacitor from which current is drawn to provide the power boost. When inactive, the reservoir capacitors charge up from the respective power supply rails. The dynamic power supply is well suited for audio amplification systems. | 02-10-2011 |
| 20090289720 | High-Efficiency Envelope Tracking Systems and Methods for Radio Frequency Power Amplifiers - High-efficiency envelope tracking (ET) methods and apparatus for dynamically controlling power supplied to radio frequency power amplifiers (RFPAs). An exemplary ET circuit includes a switch-mode converter coupled in parallel with a split-path linear regulator. The switch-mode converter is configured to generally track an input envelope signal Venv and supply the current needs of a load (e.g., an RFPA). The split-path linear regulator compensates for inaccurate envelope tracking by sourcing or sinking current to the load via a main current path. A current sense path connected in parallel with the main current path includes a current sense resistor used by a hysteresis comparator to control the switching of the switch-mode converter. The split-path linear regulator is configured so that current flowing in the current sense path is a lower, scaled version of the current flowing in the main current path. | 11-26-2009 |
| 20080211583 | SYSTEM AND METHOD FOR DYNAMIC DRAIN VOLTAGE ADJUSTMENT TO CONTROL LINEARITY, OUTPUT POWER, AND EFFICIENCY IN RF POWER AMPLIFIERS - A system and method for dynamic adjustment of drain or collector voltage of a power amplifier (PA), including a PA having a voltage input, a temperature sensor measuring ambient temperature of the PA, and an adaptive PA control processor that dynamically changes the input voltage based on the ambient temperature, achieving a desired peak power when the system is subjected to high temperatures. In a further embodiment, a power sensor measures output power of the PA, and the control processor dynamically changes the voltage based on output power when the system serves a large cell in a mobile communication infrastructure employing high power. In a further embodiment, a multistage PA and method include amplifier stages having drain or collector voltage inputs, wherein a voltage applied to the inputs are set so as to be proportional to the peak power requirements of each stage, enhancing overall efficiency. | 09-04-2008 |
| 20090278609 | Supply control for multiple power modes of a power amplifier - In one embodiment, the present invention includes an apparatus having at least two gain stages to receive incoming signals and to output amplified signals, along with multiple regulators. More specifically, a linear regulator can be coupled to the first gain stage to provide a first regulated voltage to the first gain stage, and a switching regulator coupled to the second gain stage to provide a second regulated voltage to the second gain stage. | 11-12-2009 |
| 20090278608 | Power Supply Device for Driving an Amplifier - A power supply device for driving an amplifier includes a power generator for providing a first voltage for a first power reception end of the amplifier, a power conversion unit coupled to the power generator, for converting the first voltage into a second voltage, a charge pump coupled between the power conversion unit and a second power reception end of the amplifier, for generating a third voltage for the amplifier according to the second voltage, and a control unit coupled to the power conversion unit, for controlling the power conversion unit, so as to adjust the second voltage to make the third voltage equal to a specific multiple of the first voltage. | 11-12-2009 |
| 20090278607 | Power Supply Device For Driving An Amplifier - A power supply device for driving first and second amplifiers includes a first power generator, a second power generator, a charge pump and a control unit. The first power generator provides a first voltage for first power reception ends of the first and second amplifiers. The second power generator provides a second voltage. The charge pump is coupled between the second power generator and a second power reception end of the first amplifier and between the second power generator and a second power reception end of the second amplifier, and is used for generating a third voltage for the first and second amplifiers according to the second voltage. The control unit is coupled to the second power generator and is used for controlling the second power generator, so as to adjust the second voltage to make the third voltage equal to a multiple of the first voltage. | 11-12-2009 |
| 20100141345 | AMPLIFIER SYSTEM WITH DYNAMICALLY-ADJUSTED SUPPLY VOLTAGE - An amplifier system may include an output stage configured to provide an amplified output signal at an output thereof based on an input signal, the output stage being connected between first and second supply voltages. A dynamic power supply control system provides the first and second supply voltages, the dynamic power supply being configured to adjust the first and second supply voltages as a function of the input signal such that a difference between the first and second supply voltages remains substantially constant. | 06-10-2010 |
| 20080290949 | APPARATUS AND METHOD FOR ASYMMETRIC CHARGE PUMP FOR AN AUDIO AMPLIFIER - An audio amplifier with an integrated asymmetric charge pump is provided. The audio amplifier receives VDD and VSS as power supply signals. The integrated charge pump is arranged to provide VSS from VDD, such that VSS is a negative voltage that is lower in magnitude than VDD. | 11-27-2008 |
| 20080252380 | Power Supply System - A power supply system comprises a parallel arrangement of a linear amplifier (LA) and a DC-DC converter (CO). An output of the linear amplifier (LA) is directly coupled to a load (LO) for supplying a first current (II) to the load (LO). The DC-DC converter (CO) has a converter output coupled to the load (LO) for supplying a second current ( | 10-16-2008 |
| 20080290950 | SEMICONDUCTOR INTEGRATED CIRCUIT - The semiconductor integrated circuit includes a constant voltage regulator | 11-27-2008 |
| 20080272848 | Nested transimpedance amplifier - A nested transimpedance amplifier (TIA) circuit comprises a zero-order TIA having an input and an output. A first operational amplifier (opamp) has an output and an input that communicates with said output of said zero-order TIA. A first power supply input applies a first voltage to the zero-order TIA. A second power supply input receives a second voltage. A charge pump module develops a third voltage based on the first voltage and the second voltage, wherein the third voltage is applied to the opamp. | 11-06-2008 |
| 20100264992 | AMPLIFYING CIRCUIT AND AMPLIFYING METHOD - An amplifying circuit includes: a waveform modifying unit which changes the signal value in the second section in such a manner so as to reduce the difference between the signal strength of a DC component of the input signal and the limit value that limits the variation range of the signal value in the first section; a DC component removing unit which removes the DC component of the input signal after the input signal has been modified by the waveform modifying unit; and an amplifying unit which amplifies the input signal whose DC component has been removed. | 10-21-2010 |
| 20110221533 | AMPLIFIER CIRCUIT AND METHOD OF AMPLIFYING A SIGNAL IN AN AMPLIFIER CIRCUIT - There is provided an amplifier circuit, comprising: an input, for receiving an input signal to be amplified; a power amplifier, for amplifying the input signal; a switched power supply, having a switching frequency, for providing at least one supply voltage to the power amplifier; and a dither block, for dithering the switching frequency of the switched power supply. The dither block is controlled based on the input signal. Another aspect of the invention involves using first and second switches, each having different capacitances and resistances, and using the first or second switch depending on the input signal or volume signal. Another aspect of the invention involves controlling a bias signal provided to one or more components in the signal path based on the input signal or volume signal. | 09-15-2011 |
| 20090002074 | Power Supply Control Circuit - The present invention is to provide a power supply control circuit that can effectively eliminate voltage distortion of an input signal during signal amplification. A power supply control circuit which controls a power supply voltage of a direct-current power source at a constant level and supplies the power supply voltage to an amplification circuit performing a differential operation alternately in accordance with a signal level of an input signal includes: a first transistor whose collector is connected to the direct-current power source and emitter is connected to the amplification circuit, for outputting a current; an error amplifier whose output port is connected to a base of the first transistor, for performing feedback control to hold a difference between a predetermined reference potential and a potential at the emitter of the first transistor at a constant level; and a second transistor whose emitter and base are mutually connected to the first transistor and collector is grounded, for absorbing a current. | 01-01-2009 |
| 20090096531 | RF POWER AMPLIFIER APPARATUS AND POWER SUPPLY CIRCUIT FOR CONTROLLING-POWER SUPPLY VOLTAGE TO RF POWER AMPLIFIER - The RF power amplifier apparatus has an RF power amplifier RFPA and a power-supply circuit Pwr_Cnt. The power-supply circuit controls the level of a source voltage V | 04-16-2009 |
| 20090115531 | EFFICIENT POWER AMPLIFIER - A dynamic power supply for N amplifiers includes first and second power boost circuits which temporarily boost the positive or negative power supply rail, respectively. A control circuit monitors amplifier output signal levels and provides power boost control signals to the power boost circuits, which temporarily raise the positive supply voltage above the nominal voltage level in tandem with the highest output signal from the N amplifiers and lower the negative supply voltage below the nominal voltage level in tandem with the lowest output signal level from the N amplifiers. The power boost circuits each may be coupled to a reservoir capacitor from which current is drawn to provide the power boost. When inactive, the reservoir capacitors charge up from the respective power supply rails. The dynamic power supply is well suited for audio amplification systems. | 05-07-2009 |
| 20110032038 | RF POWER AMPLIFIER APPARATUS AND POWER SUPPLY CIRCUIT FOR CONTROLLING POWER-SUPPLY VOLTAGE TO RF POWER AMPLIFIER - The RF power amplifier apparatus has an RF power amplifier and a power-supply circuit. The power-supply circuit controls the level of a source voltage supplied to the RF power amplifier in response to the level of a power-control signal. A sensing resistance produces a sense signal Vsen corresponding to a source current with respect to a source voltage. The current-control unit controls the source current I | 02-10-2011 |
| 20110234323 | AMPLIFICATION CONTROL CIRCUIT - There is provided an amplification control circuit that can adjust the amount of current being supplied to an amplifier according to a reference signal set beforehand. An amplification control circuit according to an aspect of the invention may include: a power supply section supplying a DC power set beforehand to at least one amplifier according to a reference signal set beforehand; a current control section detecting a current being supplied from the power supply section according to a ratio set beforehand and controlling the amount of current being supplied to the at least one amplifier from the power supply section; and a current adjustment section adjusting a level of the current being controlled by the current control section in order to increase or decrease the amount of current being supplied to the at least one amplifier from the power supply section. | 09-29-2011 |
| 20110018640 | TRANSMITTER UTILIZING A DUTY CYCLE ENVELOPE REDUCTION AND RESTORATION MODULATOR - A broad power band transmitter utilizing a duty cycle modulator achieves 80dB of power range for 3G signals. The present invention greatly improves the efficiency of transmitters used in mobile phones, for example, by using the duty cycle modulator during medium and low power levels of the transmitting power amplifier. The power amplifier operates in three different modes based upon the amplifier power level selected. The power amplifier operates in an EER mode during high power levels, in a DCM ERR mode during medium power levels, and in a DCM mode during low power levels. | 01-27-2011 |
| 20110115563 | AMPLIFIER CIRCUIT AND METHODS OF OPERATION THEREOF - A signal amplifying circuit and associated methods and apparatuses, the circuit comprising: a signal path extending from an input terminal to an output terminal, a gain controller arranged to control the gain applied along the signal path in response to a control signal; an output stage within the signal path for generating the output signal, the output stage having a gain that is substantially independent of its supply voltage, and a variable voltage power supply comprising a charge pump for providing positive and negative output voltages, the charge pump comprising a network of switches that is operable in a number of different states and a controller for operating the switches in a sequence of the states so as to generate positive and negative output voltages together spanning a voltage approximately equal to the input voltage. | 05-19-2011 |
| 20100164630 | Adaptive signal-feed-forward circuit and method for reducing amplifier power without signal distortion - Digital amplifying circuitry delays a digital data signal (IN | 07-01-2010 |
| 20100164631 | ELECTRONIC SYSTEM HAVING COMMON MODE VOLTAGE RANGE ENHANCEMENT - An electronic system generates at least one floating supply voltage, wherein during operation of the circuit the floating supply voltage tracks a common mode voltage of first and second differential input signals. By tracking the common mode voltage, in at least one embodiment, the floating supply voltage adjusts as the common mode voltage changes. Thus, the floating supply voltages can be based upon the peak-to-peak values of the first and second output signals without factoring in the common mode voltage. In at least one embodiment, the electronic system provides the floating supply voltages to an amplifier. The amplifier amplifies the first and second differential input signals and generates differential output signals. A differential sampling circuit samples the differential output signals to cancel the common mode voltage from the differential output signals. In at least one embodiment, an analog-to-digital converter converts the sampled differential output signals into a digital output signal. | 07-01-2010 |
| 20120242413 | AMPLIFIER CIRCUIT AND METHOD OF AMPLIFYING A SIGNAL IN AN AMPLIFIER CIRCUIT - An amplifier circuit, comprising: an input, for receiving an input signal to be amplified; a power amplifier, for amplifying the input signal; a switched power supply, having a switching frequency, for providing at least one supply voltage to the power amplifier; and a dither block, for dithering the switching frequency of the switched power supply. The dither block is controlled based on the input signal. Another aspect of the invention involves using first and second switches, each having different capacitances and resistances, and using the first or second switch depending on the input signal or volume signal. Another aspect of the invention involves controlling a bias signal provided to one or more components in the signal path based on the input signal or volume signal. | 09-27-2012 |
| 20090153250 | METHOD AND SYSTEM FOR SCALING SUPPLY, DEVICE SIZE, AND LOAD OF A POWER AMPLIFIER - Aspects of a method and system for scaling supply, device size, and load of a power amplifier (PA) are provided. In this regard parameters of a PA, and a voltage, a current, and/or a load of the PA may be configured based on a determined amplitude of a baseband signal and based on a transmit power of the PA. In this regard, the PA may be configured by configuring device size of and/or selecting one or more transistors within the PA. The load may be a transformer and may be configured by adjusting a windings ratio. The PA may comprise one or more differential pairs. In this regard, device size of the differential pair(s) may be configured based on the determined amplitude of the baseband signal and based on a transmit power of the PA. | 06-18-2009 |
| 20100321116 | METHOD AND APPARATUS FOR CONTROLLING POWER SUPPLY OF AUDIO AMPLIFIER - A method of controlling power supply voltage of an audio amplifier delays an input audio signal; estimates, with a digital signal processor, an audio output level of the delayed input audio signal based on correlations between the delayed input audio signal level and audio level change factors; sets a value of power supply voltage supplied to a power switching circuit unit in correspondence with the estimated audio output level prior to outputting the delayed input audio signal on which the estimated audio output level is based; and amplifies the delayed audio input signal to provide an audio output signal by variably controlling the power supply voltage supplied to the power switching circuit unit according to the set value of power supply voltage. | 12-23-2010 |
| 20100321115 | Class-G Line Driver Control Signal - An apparatus comprising an input, a control signal generator coupled to the input and having a control signal generator output, and an amplifier coupled to the control signal generator output, wherein a voltage supplied to the amplifier is switched based on the control signal generator output, and wherein the control signal generator output is based on a data signal in the input. Also included is an apparatus comprising circuitry configured to implement a method comprising detecting an incoming signal, calculating a derivative of the incoming signal, estimating a future incoming signal based on the derivative of the incoming signal and a time step, and providing the estimated future incoming signal to switch between a first supply voltage and a second supply voltage prior to or concurrent with an arrival of the future incoming signal at the switch, wherein the incoming signal and the future incoming signal are analog signals. | 12-23-2010 |
| 20110050349 | BOOSTED-RAIL AMPLIFIER - An amplifier device including an amplifier having an input for receiving an audio input signal and an output for sending an output signal to a load. A boosted-rail circuit is connected to a power source and has a single boosted rail connected to the BTL amplifier. Also, a common-mode circuit is coupled to the boosted-rail circuit and the BTL amplifier. The common-mode circuit sends a common-mode signal to the BTL amplifier that will dynamically track the output voltage supplied from the boosted-rail circuit to the BTL amplifier. In operation, the boosted-rail circuit reacts to the BTL amplifier and switches from a non-boost mode to a boost mode to increase the output voltage supplied to the BTL when the BTL amplifier requires additional voltage. | 03-03-2011 |
| 20110095829 | HEADPHONE AMPLIFIER CIRCUIT - A class G headphone amplifier circuit with improved power efficiency and low EMI. It may use an automatic signal level detector to detect the signal level of incoming signals and determine positive and negative power supplies for headphone amplifiers accordingly. A voltage generator may generate pairs of differential output voltages at a plurality of amplitude steps, and supply to headphone amplifiers the pair with the amplitude determined by the automatic signal level detector. As a result, headphone amplifiers are biased according to the input signal level, and the multiple voltage rails may improve power efficiency and avoid clipping. | 04-28-2011 |
| 20110102089 | SEMICONDUCTOR DEVICE AND METHOD OF CONTROLLING THE SAME - When overdriving a first power supply voltage supplied to a sense amplifier, a line for the first power supply voltage and a line for a second power supply voltage which is higher than the first power supply voltage are connected to each other by a first transistor, thereby boosting the first power supply voltage. When the first power supply voltage drops upon activation of the sense amplifier, the line for the first power supply voltage and the line for the second power supply voltage are connected to each other by a second transistor, thereby increasing the current supply capability. The first transistor and the second transistor are fully driven to operate as switches. | 05-05-2011 |
| 20100194479 | AMPLIFIER CIRCUIT AND METHODS OF OPERATION THEREOF - A signal amplifying circuit and associated methods and apparatuses, the circuit comprising: a signal path extending from an input terminal to an output terminal, a gain controller arranged to control the gain applied along the signal path in response to a control signal; an output stage within the signal path for generating the output signal, the output stage having a gain that is substantially independent of its supply voltage, and a variable voltage power supply comprising a charge pump for providing positive and negative output voltages, the charge pump comprising a network of switches that is operable in a number of different states and a controller for operating the switches in a sequence of the states so as to generate positive and negative output voltages together spanning a voltage approximately equal to the input voltage. | 08-05-2010 |
| 20100013561 | ANTI-POP CIRCUITS AND METHODS FOR AUDIO AMPLIFIERS USING VARIABLE RESISTORS - Anti-pop circuits are provided for an audio amplifier that uses a power supply voltage and a ground voltage to drive a load with an audio signal that is centered about a virtual analog ground. These anti-pop circuits include a variable resistor and a capacitor that are connected to the audio amplifier to provide a low pass filter. The variable resistor has resistance that varies in response to a voltage level of the virtual analog ground, such as a difference between a voltage level of the power supply voltage and the voltage level of the virtual analog ground. The variable resistor may be a field effect transistor having a gate that is responsive to the differences between the voltage level of the power supply voltage and the voltage level of the virtual analog ground. The capacitor may be a field effect transistor, as well. Related methods are also described. | 01-21-2010 |
| 20090002075 | AMPLIFIER WITH CONFIGURABLE DC-COUPLED OR AC-COUPLED OUTPUT - A multi-mode amplifier with configurable DC-coupled or AC-coupled output is described. In one design, the multi-mode amplifier includes an amplifier and at least one DC level shifting circuit. The amplifier receives and amplifies an input signal and provides an output signal that is suitable for DC coupling to a load in a DC-coupled mode and for AC coupling to the load in an AC-coupled mode. The at least one DC level shifting circuit performs DC level shifting for at least one (e.g., input and/or output) common-mode voltage of the amplifier and is controlled based on whether the amplifier is operating in the DC-coupled or AC-coupled mode. The amplifier operates between V | 01-01-2009 |
| 20120098601 | AMPLIFYING CIRCUIT - When an output voltage from the amplifying circuit includes a positive DC voltage, an electric current continuously flows in a power source voltage, a load, and a reference voltage in this order. As a result, the reference voltage increases so as to be a first threshold voltage or more. The detecting section detects that the reference voltage is the first threshold voltage or more. When the output voltage from the amplifying circuit includes a negative DC voltage, an electric current continuously flows in the reference voltage, the load, a grounding potential in this order. As a result, the reference voltage reduces so as to be a second threshold voltage or less. The detecting section detects that the reference voltage is the second threshold voltage or less. | 04-26-2012 |
| 20100097148 | Headphone Amplifier Circuit - A class G headphone amplifier circuit with improved power efficiency and low EMI. It may use an automatic signal level detector to detect the signal level of incoming signals and determine positive and negative power supplies for headphone amplifiers accordingly. A voltage generator may generate pairs of differential output voltages at a plurality of amplitude steps, and supply to headphone amplifiers the pair with the amplitude determined by the automatic signal level detector. As a result, headphone amplifiers are biased according to the input signal level, and the multiple voltage rails may improve power efficiency and avoid clipping. | 04-22-2010 |
| 20120044023 | Apparatus and Method for a Smooth Powerup of a Reference Signal - A circuit for providing a reference voltage can be widely used in audio applications. However, at startup an abrupt start in the reference signal can cause undesirable audible artifacts. A circuit employing feedback of a reference voltage to control the charging of a capacitor which provides the reference voltage can be used to provide a smooth startup to the reference voltage. The circuit contains a differential pair for steering a fixed current source from one path to another as the reference voltage increases. The steered current can then be mirrored into one or more current mirrors where the newly mirrored current can be squeezed to zero when the difference between a desired reference voltage and the reference voltage approaches zero. This newly mirrored current can be used to charge a capacitor which is used to provide the reference voltage. | 02-23-2012 |
| 20120025917 | Efficient amplification stage - This is disclosed an amplification stage including a first amplifier stage, a second amplifier stage, and a power supply unit, in which the output of the first stage provides the input to the second stage, and the power supply unit provides a power supply for both amplifier stages, wherein the voltage of the power supply is continuously varied in dependence of the amplitude of the signal being amplified. | 02-02-2012 |
| 20120062323 | Radio-Frequency Power Amplifier with Fast Envelope Tracking - A radio-frequency power amplifier with envelope tracking, comprising: a power RF amplifying device for amplifying a RF signal; and a switching DC/DC converter, comprising a switching device and a rectifying device, for providing said power RF amplifying device with a DC power supply at a voltage level proportional to an envelope of said RF signal; wherein said switching device is a RF power transistor; characterized in that said rectifying device, and preferably also said power RF amplifying device, is also a transistor of a same technology, connected as a two-terminal device. Preferably, said power RF amplifying device is also a transistor of said same technology. A low-pass filter can also be provided for reducing the bandwidth of the envelope signal on which the PWM signal driving the DC/DC converter depends. | 03-15-2012 |
| 20120249247 | Front-End Circuit of Low Supply-Voltage Memory Interface Receiver - A circuit includes a reference voltage generator configured to generate a first reference voltage and a second reference voltage, wherein the first reference voltage is higher than a half of a positive power supply voltage, and the second reference voltage is lower than the half of the positive power supply voltage. An n-type differential amplifier includes a first and a second NMOS transistor, wherein a gate of the first NMOS transistor is coupled to an input node, and a gate of the second NMOS transistor is configured to receive the first reference voltage. A p-type differential amplifier is operated by the positive supply voltage and includes a first and a second PMOS transistor. A gate of the first PMOS transistor is coupled to the input node, and a gate of the second PMOS transistor is configured to receive the second reference voltage. | 10-04-2012 |
| 20100289586 | METHOD FOR OBTAINING FIELD STRENGTH INFORMATION - A method for obtaining field strength information from a received electromagnetic signal by a receiver unit, in which an input voltage is generated for an operational amplifier from the received signal in the receiver unit by an input resistance and an output voltage is generated by the operational amplifier by a fixed amplification factor. The input voltage is changed until the output voltage lies within a predefined interval that includes the value of the reference voltage, and hereby the input voltage is tapped at a divider node of a voltage divider and to adjust the output voltage to the reference voltage the gate voltage of the MOS transistor, operating within a nonlinear range, and connected to the divider node is changed in such a way that the forward resistance of the MOS transistor is changed substantially logarithmically and the field strength value received by the receiver unit is determined from a comparison of the value of the present gate voltage with the quantities assigned to the gate voltage values in a memory. | 11-18-2010 |
| 20120126899 | Power Amplifier with Stabilising Network - A power amplifier circuit comprising a transistor for receiving a signal to be amplified at an input and for outputting an amplified signal at an output; a modulated power supply connected to the transistor output; and a resistive element connected at the transistor output such that a low impedance is maintained at the transistor output across a range of operational frequencies. | 05-24-2012 |
| 20120313713 | Switching Power Supply - A power supply is disclosed herein. For example, the power supply can include a switching device and an aperture generator and control module. The switching device can be configured to down-convert an input voltage and pass the down-converted input voltage to an output voltage node. The aperture generator and control module can be configured to control the switching device. In response to a power efficiency of the power supply exceeding a predetermined threshold, the aperture generator and control module can deactivate the switching device and pass the input voltage to the output voltage node. | 12-13-2012 |
| 20090058533 | Voltage generating apparatus and methods - The invention provides a voltage generating apparatus for powering at least one amplifier. The voltage generating apparatus comprises a voltage source, a switched capacitor voltage converter and a voltage detector. The voltage source supplies a first voltage to a positive voltage input terminal of the at least one amplifier. The first voltage is a positive DC voltage. The switched capacitor voltage converter is coupled to the voltage source for outputting an output voltage to a negative voltage input terminal of the at least one amplifier according to the first voltage and a predetermined voltage. The output voltage is a negative DC voltage. The voltage detector is coupled to the switched capacitor voltage converter for determining a switching frequency corresponding to the predetermined voltage according to the output voltage. The switched capacitor voltage converter increases the output voltage when the switching frequency is decreased and decreases the output voltage when the switching frequency is increased. | 03-05-2009 |
| 20120169425 | DC-DC CONVERTER SWITCHING TRANSISTOR CURRENT MEASUREMENT TECHNIQUE - A method is described comprising conducting a first current through a switching transistor. The method also comprises conducting a second current through a pair of transistors whose conductive channels are coupled in series with respect to each other and are together coupled in parallel across the switching transistor's conductive channel. The second current is less than and proportional to the first current. | 07-05-2012 |
| 20120176200 | CROSS-DIFFERENTIAL AMPLIFIER - A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches. | 07-12-2012 |
| 20120313712 | APPARATUS AND METHOD FOR A SMOOTH POWERUP OF A REFERENCE SIGNAL - A circuit for providing a reference voltage can be widely used in audio applications. However, at startup an abrupt start in the reference signal can cause undesirable audible artifacts. A circuit employing feedback of a reference voltage to control the charging of a capacitor which provides the reference voltage can be used to provide a smooth startup to the reference voltage. The circuit contains a differential pair for steering a fixed current source from one path to another as the reference voltage increases. The steered current can then be mirrored into one ore more current mirrors where the newly mirrored current can he squeezed to zero when the difference between a desired reference voltage and the reference voltage approaches zero. This newly mirrored current can he used to charge a capacitor which is used to provide the reference voltage. | 12-13-2012 |
| 20100327979 | Current Detection Apparatus and Control System Using the Same - A highly accurate current detection apparatus is realized in a one-chip LSI. An end of a current detector is connected to an analog power supply (VACC) or a virtual analog ground potential (VAG) of a voltage amplifier and an A/D converter, and a predetermined voltage is supplied between the voltage amplifier and the virtual ground potential (VAG) by a power supply. | 12-30-2010 |
| 20120274405 | AMPLIFIER - An amplifier including: an output stage having two first power supply terminals capable of receiving a first voltage defined by first positive and negative variable potentials with respect to a reference potential; and a circuit for controlling the current in transistors of the output stage with a reference value, wherein the output stage includes a first and a second MOS transistors in series between the first two terminals, the junction point of this series association defining an output terminal of the amplifier; the control circuit includes two measurement MOS transistors having their respective sources and gates coupled to the respective sources and gates of the first and second transistors of the output stage; at least one control branch, comprising transistors in series between two terminals of application of a second voltage, defines nodes connected to the gates of the output transistors, said second voltage being greater than the first one. | 11-01-2012 |
| 20120081183 | Current Saving by Reduced Modulation Code and Selective Gating of RF Signal - A polar modulation power amplifier employs both thermometer coded and binary coded amplitude modulation data. The thermometer coded amplitude modulation data selectively activates one or more equally weighted power amplifier cells. The binary coded amplitude modulation data selectively activates one or more binary weighted power amplifier cells. When less than full output power is required and the MSBs of the amplitude modulation data are zero (reducing output power at the expense of quantization noise), the power dissipated by RF signal buffers for the unused power amplifier cells corresponding to the MSBs is substantially reduced by gating off the RF signal upstream of the buffers. | 04-05-2012 |
| 20130141169 | LINEAR AMPLIFIER POWER SUPPLY MODULATION FOR ENVELOPE TRACKING - Circuitry, which includes a linear amplifier and a linear amplifier power supply, is disclosed. The linear amplifier at least partially provides an envelope power supply signal to a radio frequency (RF) power amplifier (PA) using a selected one of a group of linear amplifier supply voltages. The linear amplifier power supply provides at least one of the group of linear amplifier supply voltages. Selection of the selected one of the group of linear amplifier supply voltages is based on a desired voltage of the envelope power supply signal. | 06-06-2013 |
| 20130093521 | APPARATUS AND METHOD FOR INTERLEAVING SWITCHING IN POWER AMPLIFIER - An apparatus of a hybrid power modulator using interleaving switching is provided. The apparatus includes a linear switching unit for generating an output signal by comparing an envelope input signal and a feedback signal, an interleaving signal generator for generating an interleaving switching signal arranged not to supply the signal to input stages of P-type Metal-Oxide-Semiconductor (MOS) Field Effect Transistors (FETs) and N-type MOS FETs of power cells at the same time by comparing the output signal and a reference signal, and a switching amplifying unit for determining a level of the switching signal using the interleaving switching signal. Hence, the hybrid power modulator using the interleaving switching method in the envelope signal of the wide bandwidth maintains high efficiency and high linearity. In addition, the buck converter can use the single inductor by preventing the simultaneous on/off of the power cells. | 04-18-2013 |
| 20130127548 | APPARATUS AND METHODS FOR VOLTAGE CONVERTERS - Apparatus and methods for voltage converters are provided. In one embodiment, a voltage conversion system includes a bypass circuit and a voltage converter including an inductor and a plurality of switches configured to control a current through the inductor. The bypass circuit includes a first p-type field effect transistor (PFET), a second PFET, a first n-type field effect transistor (NFET), and a second NFET. The first and second NFET transistors and the first and second PFET transistors are electrically connected between a first end and a second end of the inductor such that a source of the first PFET transistor and a drain of the first NFET transistor are electrically connected to the first end of the inductor and such that a drain of the second PFET transistor and a source of the second NFET transistor are electrically connected to the second end of the inductor. | 05-23-2013 |
| 20130127547 | EFFICIENT SUPPLY VOLTAGE - There is disclosed an arrangement comprising: a driver stage connected to receive an input signal and generate a drive signal; a transformer comprising: a first winding of a first side of the transformer, across which winding a voltage signal is developed in dependence on the drive signal; and a second winding of the first side of the transformer, coupled to the first winding, which exhibits across it a voltage signal related to the voltage across the first winding, by swingback; and a first controller for comparing the voltage exhibited in the second winding to a first threshold voltage, and for selecting a first or a second supply voltage for the arrangement in dependence on the comparison. | 05-23-2013 |
| 20080197930 | Digital Amplifier - Recently, the use of class D audio amplifiers has become more and more widespread. In contrast to the generally employed class A-B linear amplification technology, class D allows for improved efficiency. However, the class D principle is known for its poor distortion characteristics. According to the present invention, a digital amplifier is provided for converting an input signal to a power output. The digital amplifier according to the present invention comprises a supply ripple pre-compensation circuit for compensating voltage ripples on a supply voltage supplied to bridge circuits of the digital amplifier on the basis of the input signal. By this, supply ripples in the supply voltage supplied to the bridge which have been found to cause a major part of the distortions in the output signal of the digital amplifier may be compensated. | 08-21-2008 |
