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Document Title |
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8164389 |
Overdrive protection circuit
Embodiments of circuits, apparatuses, and systems for an overdrive protection circuit arranged at an input to a primary power transistor to protect against overdrive conditions, where the overdrive...
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8130041 |
Power amplifier device
Provided is a power amplifier device. The power amplifier device includes: a cutoff unit cutting off a direct current (DC) component of a signal delivered from a signal input terminal; a circuit...
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8054129 |
Class D amplifier
A class D amplifier includes: an amplifier that generates a digital signal for driving a load based on an input signal; an attenuator that attenuates the input signal according to an attenuation...
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8022763 |
Amplifier failure detection apparatus
An amplifier failure detection apparatus for a radio transmitter that has a function for compensating for amplifier distortion of the radio transmitter and a function for determining amplifier...
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7982535 |
AMP output protective circuit for LCD panel source driver
An AMP output protective circuit for an LCD panel source driver is disclosed. To solve a problem that internal diodes of PMOS/NMOS of an AMP output circuit are turned on, embodiments are...
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7924090 |
Amplifying device
An amplifying device for setting input impedance at several GΩ to several tens of GΩ and improving an ESD withstand current rating is provided. An ECM is connected to an input terminal 21 and f...
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7855604 |
Protection circuit and method for RF power amplifiers in WLAN transceivers
A transmitter system includes a transmitter with a power amplifier. An antenna communicates with the power amplifier. A protection circuit generates a sensed signal that varies with an impedance of...
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7847632 |
Short-circuit detecting circuit
A short-circuit detecting circuit which can accurately detect an output short-circuit of a class-D amplifier by a simple circuit construction. Two comparison pulse signals are formed on the basis...
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7795966 |
Balanced amplifier with protection circuit
According to an exemplary embodiment, a balanced amplifier includes an in-phase amplifier coupled to a first input port of an output coupler and a quadrature amplifier coupled to a second input...
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7760027 |
Power amplifier output voltage reduction method
An apparatus and method are provided for reducing the output voltage in a power amplifier. The power amplifier contains a power supply, an amplifier stage, an impedance matching circuit, and a...
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7755432 |
Short circuit protection circuits and methods
In one embodiment the present invention includes a circuit comprising an amplifier, a first monitor circuit, a second monitor circuit, a third monitor circuit, and a control circuit. The amplifier...
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7710204 |
Adaptive protection circuit for a power amplifier
A radio frequency device comprises a radio frequency (RF) power amplifier (PA) operably coupled to a protection circuit for minimising voltage standing wave ratio effects, wherein the protection...
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7705673 |
Over-current sensing during narrow gate drive operation of class D output stages
Two transistors of a class D output stage are driven by complementary, variable duty cycle signals PWM+ and PWM−. When the pulse width of the PWM+ signal becomes too narrow for reliable operation o...
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7696827 |
Power amplifier system provided with improved protection function
A power amplifier system including a power terminal, a ground terminal, an output terminal, a ripple terminal, a control terminal to which a control signal is supplied from outside, a power...
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7692491 |
Radio-frequency power amplifier
A radio-frequency power amplifier for preventing a final-stage HBT from being destroyed is provided. To this end, a radio-frequency multistage power amplifier of the present invention includes: a...
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7626456 |
Overdrive control system
An overdrive control system includes a voltage controlled current source to deliver a compensation current, and being between a first voltage reference and an internal node, which is connected to...
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7619481 |
Circuit for inhibiting over-current in power amplifier
A power amplifier drives a load connected to a first output terminal and a second output terminal. When generation of over-current is detected by the current detection section, the output amplifier...
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7595696 |
Power amplifier
A power amplifier including an active device having at least one heterjunction bipolar transistor based on a compound semiconductor; a diode connected between the base and the emitter of the...
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7586369 |
Pulse modulation type electric power amplifier
A pulse modulation type electric power amplifier includes a pulse modulator that receives as input a clock and an input signal, and converts the input signal to a pulse train, an output control...
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7551034 |
Saturation handling
Saturation handling for preventing a power amplifier from going into a saturation condition is disclosed.
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7525389 |
Signal amplifier circuit with a limiting voltage device
A signal amplifier circuit includes a negative feedback amplifier circuit having an output terminal, a first voltage limiting device for limiting the output voltage from the negative feedback...
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7489199 |
Saturation detector and warning circuit including clamp
A saturation detection and warning circuit having an adaptive threshold voltage is disclosed. The disclosed circuit can also be used to detect the impending drop out of the low drop out linear...
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7482877 |
Power protecting apparatus and method for power amplifier
A power protecting apparatus and method of a power amplifier for removing backward voltages and preventing a hard damage within a circuit by connecting an output terminal of a DC-DC converter with...
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7477107 |
Protection circuit and method for RF power amplifiers in WLAN transceivers
A protection circuit for a power amplifier of a radio frequency transmitter includes a sensing circuit that generates a sensed signal based on an output of the power amplifier. A reference signal...
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7459979 |
Semiconductor indicator for voltage diagnostics in power amplifiers
A semiconductor indicator for quantitatively diagnosing voltage conditions in high power transistor devices is provided. The semiconductor indicator includes a first transistor and a second...
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7449959 |
Methods and apparatus to detect impedance at an amplifier output
Methods and apparatus to detect impedance at an amplifier output are described. In one example, a method of determining a relative value of an amplifier output load may include determining a...
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7394312 |
Re-configurable amplifier protection apparatus and method
The present invention is directed to an amplifier, which is able to re-configure its internal protection circuits based on an output signal level. This allows the amplifier to apply the best...
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7391267 |
Output circuit
A patterning area of an output circuit is reduced while securing strong enough ESD tolerance. In the output circuit of this invention, an output of a first amplifier and an output of a second...
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7362871 |
Audio amplifier circuit and audio IC having the same
In the present invention, in parallel with a resistor which determines an amplification rate being fed back from an output to an input of an output stage OP amp in an audio amplifier circuit,...
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7339424 |
Apparatus and method for controlling temperature of electronic apparatus
In an embodiment of this invention, if a state, in which duty ratio of a PWM signal is kept equal to or greater than a predetermined value, has been maintained for a first time period, the duty...
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7332969 |
Output offset protection for power amplifier
A output offset protection circuit provides protection of the load and the power amplifier through monitoring the temperature of the power transistor in the operational amplifier to detect fault...
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7330072 |
Circuit for power amplification
A radio frequency (RF) power amplifier, including an external control loop and a protection circuit, which functions to maintain a constant output power during variations in impedance on the RF...
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7327187 |
Method, circuit and power amplifier for detecting a fault, and method of protecting a circuit in a power amplifier from a fault occurrence
In a method of detecting a fault in a class D amplifier, an amplifier output signal is generated based on inverting a pulse width modulation signal corresponding to received audio data. The...
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7298852 |
Dynamic power sharing in a multi-channel sound system
A signal processing system for use in a multichannel audio system. The signal processing system includes a first channel having a first audio signal. A second channel is included that has at least...
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7282997 |
Thermal coupling device
A micro-electronic power amplifier that defines a uniform thermal impedance includes an output stage including a single transistor array including a plurality of emitter leads and a single thermal...
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7276974 |
Method and apparatus for protecting RF power amplifiers
Method and apparatus are provided for protecting radio frequency (RF) power amplifiers. A circuit (10) is provided for limiting a supply current to a first stage (Q3) of the RF power amplifier...
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7262667 |
Radio frequency power amplifier
A radio frequency (RF) power amplification circuit including a power amplifier is provided for preventing breakdown of the power amplifier. The power amplifier includes an input for receiving RF...
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7259618 |
Systems and methods for load detection and correction in a digital amplifier
Systems and methods for detecting the impedance of an output load coupled to a digital amplifier and compensating for changes in the response of the amplifier. One embodiment of the invention is...
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7205834 |
Power amplifier
In a power amplifier driven by a pulse width modulation (PWM) signal, a first pair of drive pulses opposite in level to each other is formed from a first pulse width modulation signal whose...
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7205840 |
Wideband CMOS gain stage
A CMOS gain stage includes biasing circuitry configured to insure saturation of a subsequent stage without a source follower circuit. The CMOS gain stage is optionally powered by a supply voltage...
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7145396 |
Method and apparatus for protecting devices in an RF power amplifier
A method and apparatus are provided for use with a power amplifier for protecting active devices on the power amplifier. A peak detector is used by control circuitry to detect the presence of a...
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7138864 |
Overcurrent protection in amplifier topologies employing DC isolation
An amplifier having output switch circuitry is described. A sense resistor is operable to transmit an output current associated with the output switch circuitry. Low-voltage circuitry is operable...
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7102445 |
Power amplifier module
An amplifier 2c amplifies a transmit signal and outputs the amplified transmit signal to an antenna 10. A drive current for driving the amplifier 2c is inputted to a drive current input terminal 7....
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7075373 |
Overcurrent protection circuit with fast current limiting control
An overcurrent protection circuit for a power transistor includes a transconductance amplifier and a bias current circuit. The transconductance amplifier receives a first signal indicative of the...
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7071776 |
Systems and methods for controlling output power in a communication device
A mismatch detector including a directional device adapted to couple signals across the device and a detector coupled to a port on the directional device and configured to measure a reflected power...
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7005924 |
Current limiting circuit with rapid response feedback loop
The current limiting circuit of the present invention includes a transconductance amplifier having two outputs and forming a conventional feedback loop. A first output connects to an output...
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6980058 |
Amplifier circuitry
Input signal amplified by an input amplifier is delivered via a voltage limiter circuit to a power amplifier, and a speaker is driven by the signal amplifier by the power amplifier. Voltage...
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6954104 |
Method and system for monitoring a deliverable radio frequency power of an amplifier operable on a monolithic microwave integrated circuit
A method and system are described for monitoring a deliverable radio frequency (RF) power of an amplifier operable on a monolithic microwave integrated circuit (MMIC). According to an exemplary...
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6949977 |
Circuit arrangement having a transimpedance amplifier connected to a current limiter circuit
A circuit arrangement is provided which has the advantage of limiting the magnitude of the current to a transimpedance amplifier (TIA) circuit or a current to voltage converter during an overdrive...
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6943629 |
Transient protection circuit of Darlington amplifier
A protection circuit for Darlington amplifiers prevents destructive voltage overshoot conditions from occurring. The Darlington amplifier has a pair of transistors connected in a Darlington...
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