A chopper-stabilized amplifier includes a first transconductance amplifier and a first chopper circuit coupled to an input of the first transconductance amplifier. A second chopper circuit is coupled to an output of the first transconductance amplifier. The chopper-stabilized amplifier also includes second and third transconductance amplifiers having inputs coupled to the output of the first transconductance amplifier. The second transconductance amplifier produces an output responsive to a first notch clock signal having a first phase relative to the chopping of the second chopper circuit. The third transconductance amplifier produces an output responsive to a second notch clock signal having a second phase relative to the first phase. The output signals produced by the second and third transconductance amplifiers are added to filter ripple noise at the outputs of the second and third transconductance amplifiers.

A signal amplifier circuit having high power supply rejection ratio includes: a pre-amplifier which generates a driving signal at a driving control node; and a driving circuit which converts an input power to an output power. The driving circuit includes: a driving transistor, having a first terminal coupled to the input power and a second terminal coupled to the output power; and a power rejection circuit which includes a noise selection circuit. When the driving transistor operates in its linear region, the power rejection circuit senses an AC component of a power noise of the input power to generate an operation noise signal. The power rejection circuit generates the power rejection signal in AC form according to the operation noise signal to reject the power noise so as to increase the power supply rejection ratio.

Systems and methods are provided for which a chopper modulator and a chopper demodulator of a chopped apparatus having a variable chopper frequency are described. A feedback path is used to reduce ripples and/or remaining offsets as a result of the variable chopper frequency.

A capacitive-coupled chopper instrumentation amplifier includes a first chopper, a first gain stage, a capacitive isolation stage electrically coupled between inputs of the first gain stage and the first chopper, a second gain stage, a second chopper electrically coupled between outputs of the first gain stage and inputs of the second gain stage, clamping circuitry electrically coupled between the inputs of the first gain stage and a reference voltage rail, and a controller. The controller is configured to (a) detect a change in a first common-mode voltage exceeding a threshold value, the first common-mode voltage being a common-mode voltage at the inputs of the amplifier, and (b) in response to detecting the change in the first common-mode voltage exceeding the threshold value, cause the clamping circuitry to clamp the inputs of the first gain stage to the reference voltage rail.

Disclosed are a radio frequency power amplifier for inhibiting a harmonic wave and stray, a chip and a communication terminal. The radio frequency power amplifier comprises a power source, an LDO circuit, a harmonic inhibition unit, a stray inhibition unit, an amplifying unit, and a low-pass matching network. On the one hand, by means of the power source being connected to the harmonic inhibition unit, harmonic waves and stray of the power source at a resonant frequency are inhibited. Additionally, by means of the stray inhibition unit reducing the gain of the amplifying unit at a resonant frequency, output of stray is reduced. On the other hand, by means of the low-pass matching network being embedded at an output end of the radio frequency power amplifier, harmonic waves and the stray of a radio frequency signal amplified by the amplifying unit at different frequencies is effectively inhibited.

The outphasing power combiner circuit includes a transformer having a primary coil coupled to a first power amplifier (PA) and a second PA, and a secondary coil. The secondary coil supplies a current to an antenna based on a first direction of a first phase of a first amplified constant-envelope signal in the primary coil with respect to a second phase of a second amplified constant-envelope signal in the primary coil. The outphasing power combiner circuit further includes load impedance coupled between a median point of the primary coil and ground. The load impedance dissipates the current based on a second direction of the first phase of the first amplified constant-envelope signal in the primary coil with respect to the second phase of the second amplified constant-envelope signal in the primary coil, which results in improved power efficiency.

According to an exemplary embodiment, a capacitively coupled continuous-time delta-sigma modulator includes an instrumentation amplifier amplifying an input voltage to an output voltage of a predetermined magnitude, a delta-sigma modulator outputting a bit signal quantized depending on a sampling frequency based on the output voltage and to convert the bit signal into a digital-to-analog conversion voltage, and a ripple reduction loop unit generating a demodulation voltage, in which a ripple is removed from the output voltage, depending on an RRL operating frequency to feed the demodulation voltage back to the instrumentation amplifier. The RRL operating frequency is equal to the sampling frequency.

A chopper stabilized amplifier includes a first transconductance amplifier, first chopping circuitry coupled to an input of the first transconductance amplifier for chopping an input signal and applying the chopped input signal to the input of the first transconductance amplifier, and second chopping circuitry coupled to an output of the first transconductance amplifier for chopping an output signal produced by the first transconductance amplifier. A ping-pong notch filter is connected to an output of the second chopping circuitry and performs an integrate and transfer function on a chopped output signal produced by the second chopping circuitry to filter ripple voltages. The ping-pong notch filter includes parallel connected first and second notch filters, each of which has an input coupled to the output of the second chopping circuitry.

The present invention relates to an amplification device (10) of an input signal comprising: a first amplification stage (12), a second amplification stage (14), each amplification stage (12, 14) comprising: a switching circuit (22), the switching circuit (22) being able to generate, as output (22A, 22B), a switched signal having at least two states, and an inductive element (24) able to smooth the switched signal to obtain a smoothed signal (I1, I3), the smoothed signal (I1, I3) having a useful component and a stray component. The amplification device (10) further comprises a compensation circuit (16), for each amplification stage (12, 14), able to generate a compensation signal (I2, I4) of the stray component of the smoothed signal (I1, I3) generated in the inductive element (24) of the corresponding amplification stage (12, 14).

A capacitive-coupled chopper instrumentation amplifier includes a first chopper, a first gain stage, a capacitive isolation stage electrically coupled between inputs of the first gain stage and the first chopper, a second gain stage, a second chopper electrically coupled between outputs of the first gain stage and inputs of the second gain stage, clamping circuitry electrically coupled between the inputs of the first gain stage and a reference voltage rail, and a controller. The controller is configured to (a) detect a change in a first common-mode voltage exceeding a threshold value, the first common-mode voltage being a common-mode voltage at the inputs of the amplifier, and (b) in response to detecting the change in the first common-mode voltage exceeding the threshold value, cause the clamping circuitry to clamp the inputs of the first gain stage to the reference voltage rail.