A low dropout regulator includes a PMOS power transistor, a feedback network, an error amplifier and an active enhanced PSRR unit. The PMOS power transistor has a first end coupled to an input voltage, and a second end coupled to a load and the feedback network. The error amplifier receives a feedback signal generated from the feedback network, compares the feedback signal with a reference voltage to generate a difference value, and amplifies the difference value to generate an error signal. The active enhanced PSRR unit has one end coupled to the first end, and another end coupled to a control end of the PMOS power transistor and the error amplifier, detects an input voltage of the first end, and correspondingly adjusts a voltage of the control end to stabilize a voltage between the control end and the first end according to a variation of the input voltage.

A motion sensor device comprises: a reverse electrowetting-on-dielectric (REWOD) generator configured to generate alternating current (AC) based on motion; a motion sensor configured to measure motion data; and a wireless motion sensor read-out circuit coupled to the REWOD generator and the motion sensor, the wireless motion sensor read-out circuit configured to transmit the motion data and operate on the AC from the REWOD generator.

The present application discloses a transconductance amplifier and a related chip. The transconductance amplifier is configured to generate an output current according to a positive input voltage and a negative input voltage, wherein the transconductance amplifier includes: an input stage, configured to receive the positive input voltage and the negative input voltage and generate a positive output current and a negative output current, wherein the input stage includes: a first transistor, wherein a gate thereof is coupled to the positive input voltage; a second transistor, wherein a gate thereof is coupled to the negative input voltage; a first resistor, serially connected between the first transistor and the second transistor; a third transistor, wherein a source of the third transistor is coupled between the first resistor and the first transistor, and a drain of the third transistor is configured to output the positive output current; and a fourth transistor.

A fully differential rail-to-rail-output amplifier includes a differential input inverter pair, folded cascode pair, class AB control pair, and class AB output rail-to-rail pair. A drain associated with the folded cascode pair is operatively coupled to the class AB control pair, and the drain associated with the folded cascode pair is unconnected to the current source associated with the class AB control pair. A method of providing fully differential rail-to-rail-output amplification includes coupling a folded cascode pair operatively to a differential input inverter pair, coupling a drain associated with the folded cascode pair operatively to a class AB control pair, and coupling a class AB output rail-to-rail pair operatively to the class AB control pair.

A decision feedback equalizer circuit includes first and second equalizers implemented in parallel. Each equalizer includes: an adder; and a comparator configured to alternatingly perform refreshing and sampling for a differential signal output from the adder. The comparator includes: a differential amplifier configured to output a differential signal having same values in a refresh period, and output a differential signal corresponding to the differential signal output from the adder in a sampling period; and a latch circuit configured to perform a decision operation based on a comparison between two signals that form the differential signal output from the differential amplifier, and to latch a decision result. The adder in the first equalizer controls the differential signal based on the decision in the second equalizer, and the adder in the second equalizer controls the differential signal based on the decision in the first equalizer.

The present application discloses a transconductance amplifier and a related chip. The transconductance amplifier is configured to generate an output current according to a positive input voltage and a negative input voltage, wherein the transconductance amplifier includes: an input stage, configured to receive the positive input voltage and the negative input voltage and generate a positive output current and a negative output current, wherein the input stage includes: a first transistor, wherein a gate thereof is coupled to the positive input voltage; a second transistor, wherein a gate thereof is coupled to the negative input voltage; a first resistor, serially connected between the first transistor and the second transistor; a third transistor, wherein a source of the third transistor is coupled between the first resistor and the first transistor, and a drain of the third transistor is configured to output the positive output current; and a fourth transistor

A fully differential rail-to-rail-output amplifier includes a differential input inverter pair, folded cascode pair, class AB control pair, and class AB output rail-to-rail pair. A drain associated with the folded cascode pair is operatively coupled to the class AB control pair, and the drain associated with the folded cascode pair is unconnected to the current source associated with the class AB control pair. A method of providing fully differential rail-to-rail-output amplification includes coupling a folded cascode pair operatively to a differential input inverter pair, coupling a drain associated with the folded cascode pair operatively to a class AB control pair, and coupling a class AB output rail-to-rail pair operatively to the class AB control pair.

Disclosed herein are circuits, devices and methods that address challenges associated with power amplifier systems. A power amplifier system includes two or more fast error amplifiers coupled to corresponding power amplifiers. The fast error amplifiers are configured to generate envelope tracking signals based on a signal envelope, the envelope tracking signals modifying a DC-DC regulated voltage from a DC-DC converter to more efficiently operate the power amplifiers. By splitting the envelope tracking between two or more fast error amplifiers and amplification between corresponding two or more power amplifiers, the power, frequency or bandwidth, linearity, signal-to-noise ratio, efficiency, or the like of the power amplifier system can be improved. Wireless communications configurations with such power amplifier systems can provide uplink carrier aggregation and/or cellular signals based on standards and protocols that require increased bandwidth and/or power.

An amplifier including a signal input terminal, at least one signal output terminal, a first and a second cascode amplifier circuits, a capacitor and a loading circuit. The signal input terminal receives an input signal. The first cascode amplifier circuit includes a first and a second input terminals and a first and a second output terminals. The first input terminal coupled to the signal input terminal receives the input signal. The second cascode amplifier circuit includes a third and a fourth input terminals and a third output terminal. The third input terminal is coupled to the first output terminal, and the third output terminal is coupled to the second input terminal. Two terminals of the capacitor are coupled to the fourth input terminal and the first output terminal respectively. A terminal of the loading circuit is coupled to the third output terminal, and another terminal of the loading circuit is coupled to the second output terminal. At least one of two terminals of the loading circuit is further coupled to the at least one signal output terminal.

Disclosed herein are circuits, devices and methods that address challenges associated with power amplifier systems. A power amplifier system includes two or more fast error amplifiers coupled to corresponding power amplifiers. The fast error amplifiers are configured to generate envelope tracking signals based on a signal envelope, the envelope tracking signals modifying a DC-DC regulated voltage from a DC-DC converter to more efficiently operate the power amplifiers. By splitting the envelope tracking between two or more fast error amplifiers and amplification between corresponding two or more power amplifiers, the power, frequency or bandwidth, linearity, signal-to-noise ratio, efficiency, or the like of the power amplifier system can be improved. Wireless communications configurations with such power amplifier systems can provide uplink carrier aggregation and/or cellular signals based on standards and protocols that require increased bandwidth and/or power.