An electronic driving circuit for a microfluidic device, having a number of synchronized driving stages to generate a respective driving signal for each electrode or group of electrodes of the microfluidic device, the driving signals having a desired amplitude, frequency and phase-shift. Each driving stage has a switching-mode amplifier stage to receive a clock signal and a target signal and to generate, at an output thereof, an output signal defining a respective driving signal. The amplifier stage has: a switching module, coupled to a first internal node and controlled by the clock signal for selectively bringing the first internal node to a control signal; a filter module, coupled between the first internal node and the output, to provide the output signal; and a feedback module.

Techniques are described for using valley detection for supply voltage modulation in power amplifier circuits. Embodiments operate in context of a power amplifier circuit configured to be driven by a supply voltage generated by a supply modulator and to receive an amplitude-modulated (AM) signal at its input. The output of the power amplifier circuit can be fed to a valley detector that can detect a valley level corresponding to the bottom of the envelope of the AM signal. The detected valley level can be fed back to the supply modulator and compared to a constant reference. In response to the comparison, the supply modulator can vary the supply voltage to the power amplifier circuit in a manner that effectively tracking the envelope of the power amplifier circuit's output signal, thereby effectively seeking a flat valley for the output signal's envelope.

An electronic driving circuit for a microfluidic device, having a number of synchronized driving stages to generate a respective driving signal for each electrode or group of electrodes of the microfluidic device, the driving signals having a desired amplitude, frequency and phase-shift. Each driving stage has a switching-mode amplifier stage to receive a clock signal and a target signal and to generate, at an output thereof, an output signal defining a respective driving signal. The amplifier stage has: a switching module, coupled to a first internal node and controlled by the clock signal for selectively bringing the first internal node to a control signal; a filter module, coupled between the first internal node and the output, to provide the output signal; and a feedback module.

A radio frequency signal having a constant amplitude is modulated by a digital modulation signal and a radio frequency input signal whose amplitude changes stepwise is generated. The radio frequency input signal is input into a power amplifier that is an evaluation target. A period in which an amplitude of the radio frequency input signal is constant is defined as a measurement period and an output signal of the power amplifier is measured in each of measurement periods in which amplitudes of the radio frequency input signal are different from each other.

A communication circuit, including a first supply modulator configured to provide a first supply voltage; a first power amplifier configured to generate a first output signal by amplifying a first input signal corresponding to a first operation frequency band, a second power amplifier configured to generate a second output signal by amplifying a second input signal corresponding to a second operation frequency band; and a switching circuit configured to selectively provide the first supply voltage from the first supply modulator to the second power amplifier based on a first switching signal according to an operation node.

A switching power amplifier includes logic circuitry that generates first and second components of a differential signal, based on received amplitude code and a delayed version of the same. The amplitude code includes a sign and a magnitude. When the sign is positive, a first logic path is configured to generate the first component based on the received amplitude code and the second logic path is configured to generate the second component based on the delayed amplitude code. When the sign is negative, the first logic path is configured to generate the first component based on the delayed amplitude code and the second logic path is configured to generate the second component based on the received amplitude code. The switching power amplifier further includes a differential-to-single ended conversion circuit configured to generate a single-ended signal based on the differential signal.

A switching power amplifier includes logic circuitry that generates first and second components of a differential signal, based on received amplitude code and a delayed version of the same. The amplitude code includes a sign and a magnitude. When the sign is positive, a first logic path is configured to generate the first component based on the received amplitude code and the second logic path is configured to generate the second component based on the delayed amplitude code. When the sign is negative, the first logic path is configured to generate the first component based on the delayed amplitude code and the second logic path is configured to generate the second component based on the received amplitude code. The switching power amplifier further includes a differential-to-single ended conversion circuit configured to generate a single-ended signal based on the differential signal.

A dual-output and dual-mode supply modulator, a two-stage power amplifier using the same, and a supply modulation method therefor are provided. In order to improve the performance of a two-stage power amplifier used in a transmitter of a wireless communication system, the dual-output and dual-mode supply modulator according to the present invention may simultaneously supply an envelope tracking signal to a main amplification stage of the two-stage power amplifier and an average power tracking signal to an auxiliary amplification stage thereof. To this end, the dual-output and dual-mode supply modulator according to the present invention outputs two supply voltages and supports two operation modes. As such, it is possible to improve the efficiency of the two-stage power amplifier over a wide output power range with the use of a single supply modulator by employing envelope tracking on the main amplification stage and average power tracking on the auxiliary amplification stage in high output power regions or employing average power tracking both on the main amplification stage and auxiliary amplification stage in low output power regions.

Provided is a power amplification module that includes: a first amplification circuit that amplifies a first signal and outputs the amplified first signal as a second signal; a second amplification circuit that amplifies the second signal and outputs the amplified second signal as a third signal; and a feedback circuit that re-inputs/feeds back the second signal outputted from the first amplification circuit to the first amplification circuit as the first signal. The operation of the first amplification circuit is halted and the first signal passes through the feedback circuit and is outputted as the second signal at the time of a low power output mode.

A wideband polar modulation transmitter includes a power amplifier (PA), a PA driver, a dynamic power supply (DPS), a PA driver V.sub.H controller, and a phase modulator. The phase modulator modulates a radio frequency (RF) carrier by an input phase modulating signal PM(t) to produce a phase modulated RF carrier. Meanwhile, the DPS produces a DPS voltage for the PA that follows an input amplitude modulating signal AM(t). Using the phase modulated RF carrier, the PA driver generates a PA drive signal V.sub.DRV for driving the PA. The PA drive signal V.sub.DRV has a high drive level V.sub.H and a low drive level V.sub.L. The PA driver V.sub.H controller is configured to control the magnitude of the high drive level V.sub.H so that it remains sufficiently high to force the PA to operate in a compressed mode (C-mode) most of the time but lowers the high drive level V.sub.H to force the PA to operate in a product mode (P-mode) during times low-magnitude events occur in the DPS voltage.