1601results about "Gated amplifiers" patented technology

A radio frequency (RF) transmit/receive switch. The transmit/receive switch comprises an impedance matching circuit and a voltage scaling circuit. The impedance matching circuit matches an incoming RF signal to a low noise amplifier and an outgoing RF signal from a power amplifier. The voltage scaling circuit, coupled to the impedance matching circuit, the power amplifier, and the low noise amplifier, attenuates the outgoing RF signal to a scaled signal within a breakdown voltage of a transistor device in the low noise amplifier during transmission of the outgoing RF signal.

An amplification architecture or system is provided having a multiple amplifier system that switches modes of operation between operation in a component mode and a composite mode based on a characteristic of an input signal relative to a threshold level. In the component mode, the components of the input signal are employed to different terminals of the multiple amplifier system that provide a reconstructed amplified representation of the input signal. In the composite mode, the input signal is amplified to provide an amplified representation of the input signal.

A scalable periphery tunable matching power amplifier is presented. Varying power levels can be accommodated by selectively activating or deactivating unit cells of which the scalable periphery tunable matching power amplifier is comprised. Tunable matching allows individual unit cells to see a constant output impedance, reducing need for transforming a low impedance up to a system impedance and attendant power loss. The scalable periphery tunable matching power amplifier can also be tuned for different operating conditions such as different frequencies of operation or different modes.

Various embodiments of methods and apparatus for an amplifier with wide output voltage swing are disclosed. The amplifier may include multiple output stages, each associated with a distinct supply voltage. Each output stage may contribute current to the output of the amplifier over a range of amplifier output voltages and these ranges may overlap. Each output stage may contribute current until the amplifier output voltage reaches the supply voltage associated with that output stage. The amplifier output may be as great as the largest supply voltage minus a drop equal to Rdson for an output transistor multiplied by the output current. In a CMOS implementation, this voltage drop may be approximately 0.15V. When the amplifier output voltage is close to the supply voltage associated with an output stage, both that output stage and the output stage associated with the next highest supply voltage may contribute to the amplifier output.

A power amplifier (PA) envelope power supply, which provides an envelope power supply signal to radio frequency (RF) PA circuitry, and a process to prevent undershoot of the PA envelope power supply is disclosed. The process includes determining if an envelope control signal to the PA envelope power supply has a step change from a high magnitude to a low magnitude that exceeds a step change limit. Such a step change may cause undershoot of the PA envelope power supply. As such, if the step change exceeds the step change limit, the envelope control signal is modified to use an intermediate magnitude for period of time. Otherwise, if the step change does not exceed the step change limit, the envelope control signal is not modified.

An output voltage amplifier, and a driving device of a liquid crystal display using the same are disclosed. The output voltage amplifier includes: an amplifying unit to generate first and second signals corresponding to a gray voltage input to a first input terminal and a feedback signal input to a second input terminal, and to output a first voltage by using first and second switches driven to be on or off according to the first and second signals; an output unit to apply the first and second data signals to the first and second pixels by using third and fourth switches turned on or off according to the first and second signals; and a feedback circuit unit to selectively supply one of the first voltage and the first and second data signals to the second input terminal. Heating characteristics and a slew rate can be improved.

A direct current (DC)-DC converter that includes a first switching converter and a multi-stage filter is disclosed. The multi-stage filter includes at least a first inductance (L) capacitance (C) filter and a second LC filter coupled in series between the first switching converter and a DC-DC converter output. The first LC filter has a first LC time constant and the second LC filter has a second LC time constant, which is less than the first LC time constant. The first switching converter and the multi-stage filter form a feedback loop, which is used to regulate the first switching power supply output signal based on the setpoint. The first LC filter includes a first capacitive element having a first self-resonant frequency, which is about equal to a first notch frequency of the multi-stage filter.

A power amplifier (PA) provides dynamic stability and gain control for linear and non-linear operation. The PA operates with a baseband processor and a transmitter, in which the PA receives a signal from the transmitter for power amplification prior to transmission of the signal. The PA is configured to select between the linear mode of operation and the non-linear mode of operation, in which device scaling within the PA is achieved by changing a device sizing of at least one stage of the PA. Further to changing the device size, the PA changes biasing resistance and impedance of a matching network in response to the changing of the device size to control power output and stability for the PA.

Provided is a power amplifier which fits to a deep-submicron technology in radio frequency wireless communication. The power amplifier includes a cascode including a first transistor which receives and amplifies an input signal, and a second transistor which is connected to the first transistor in series and operated by a DC bias voltage; a third transistor which is connected between the cascode and an output end, operated by a dynamic gate bias and outputting a signal; and a voltage divider which includes first and second capacitors that are connected between the output end, i.e. a drain of the third transistor, and a ground in series, and provides the dynamic bias to a gate of the third transistor.

There is disclosed a multi-stage amplifier comprising: a first amplifier stage; a second amplifier stage; a first voltage supply stage arranged to provide a supply voltage to the first amplifier in dependence on an average power of a signal to be amplified; and a second voltage supply stage arranged to provide a supply voltage to the second amplifier in dependence on an instantaneous power of a signal to be amplified.

A multi-band radio module for selectively supplying received signals in a plurality of frequency bands to a low noise amplifier via an input impedance matching circuit by switching over the operation mode of the low noise amplifier is comprised of: a pre-stage amplification unit including a plurality of fundamental amplifiers connected to one another in parallel, the fundamental amplifiers sharing a load impedance connected to a source voltage and a grounded degeneration impedance and having input signal lines commonly connected to an input impedance matching circuit; a post-stage amplifier to which the output signals of the plurality of fundamental amplifiers are commonly inputted; and a bias control unit for selectively turning on the fundamental amplifiers, wherein the input impedance of the low noise amplifier is selectively optimized for the matching circuit depending on the RF band to be received.

A power management system for a multi-carriers transmitter is disclosed. The power management system includes a first switcher having a control input and a power output, and a second switcher having a control input and a power output. Also included is a mode switch having a mode control input, wherein the mode switch is adapted to selectively couple the power output of the first switcher to the power output of the second switcher in response to a mode control signal received by the mode control input. Further included is a control system adapted to generate the mode control signal. The control system is coupled to the mode control input of the mode switch.

An electronic circuit comprising a transistor-based RF (radio frequency) power amplifier (112) having balanced outputs (172, 176), a transistor-based receiver RF amplifier (116) having balanced inputs (152, 156) ohmically connected to said balanced outputs (172, 176) respectively of said RF power amplifier (112), and a balun (114) having a primary (182, 186) and a secondary (188), said primary (182, 186) having primary connections and a supply connection (185) of said primary (182, 186) intermediate said primary connections and said primary connections ohmically connected both to said balanced outputs (172, 176) of said RF power amplifier (112) respectively and to said balanced inputs (152, 156) of said receiver RF amplifier, thereby to switchlessly couple RF between the balun (114) and the RF power amplifier (112) and switchlessly couple RF between the balun (114) and the receiver RF amplifier (116). Other electronic circuits, processes, devices and systems are disclosed.

A differential circuit and an amplifier circuit for reducing an amplitude difference deviation, performing a full-range drive, and consuming less power are disclosed. The circuit includes a first pair of p-type transistors and a second pair of n-type transistors. A first current source and a first switch are connected in parallel between the sources of the first pair of transistors, which are tied together, and a power supply VDD. A second current source and a second switch are connected in parallel between the sources of the second pair of transistors, which are tied together, and a power supply VSS. The circuit further includes connection changeover means that performs the changeover of first and second pairs between a differential pair that receives differential input voltages and a current mirror pair that is the load of the differential pair. When one of the two pairs is the differential pair, the other is the current mirror pair. In a differential amplifier circuit, there is provided an added transistor connected in parallel to a transistor, which is one transistor of a differential pair transistors, whose control terminal is a non-inverting input terminal. The added transistor has a control terminal for receiving a control voltage which is set so that, when an input voltage applied to the non-inverting input terminal is in a range in which the transistor whose control terminal is the non-inverting input terminal is turned off, the added transistor is turned on.

A microcontroller includes a wide band, high gain amplifier on-chip capable of driving a 32 ohm speaker. The amplifier is controllable by the microcontroller processor to either enable or disable the amplifier and switch between multiple modes of power. In one embodiment, one or more such amplifiers are situated anywhere on the integrated circuit die including at the corners of the die.