Multi-level envelope tracking systems are disclosed. In certain embodiments, a method of envelope tracking includes amplifying a radio frequency signal using a power amplifier, supplying power to the power amplifier using a power amplifier supply voltage, generating a plurality of delay-controlled regulated voltages based on controlling a delay of a plurality of regulated voltages using a controllable delay circuit, generating a modulator output voltage at a modulator output of a modulator, providing filtering using a first filter coupled between the modulator output and the power amplifier supply voltage, and controlling activation of a plurality of switches of the modulator based on an envelope of the radio frequency signal. The plurality of switches are each coupled between the modulator output and a corresponding one of the plurality of delay-controlled regulated voltages.

Provided is a differential amplifier comprising: a first differential amplification circuit that has a first input terminal, a second input terminal, a first output terminal and a second output terminal which respectively output a first output signal and a second output signal; an RC filter that filters the first output signal and the second output signal and outputs them; a second differential amplification circuit that has a third input terminal and a fourth input terminal to which the first output signal and the second output signal filtered by the RC filter are respectively input and a third output terminal which outputs a third output signal; and a third amplification circuit that has a fifth input terminal to which the third output signal is input and a fourth output terminal which outputs a fourth output signal according to the third output signal.

A tracker circuit is provided that includes a switched-capacitor circuit configured to generate a plurality of discrete voltages based on a first input voltage; a supply modulator configured to selectively output at least one of the plurality of discrete voltages to a power amplifier; a bypass path configured to bypass the switched-capacitor circuit and the supply modulator to output the first input voltage to the power amplifier; and a switch configured to switch between a connection and a disconnection of the bypass path.

An instrumentation amplifier can include: an input port configured to receive a sensor signal; a first-stage amplifier configured to amplify the sensor signal to obtain a first intermediate signal; a first high-pass filter circuit, having input terminals coupled to output terminals of the first-stage amplifier, and being configured to eliminate a signal that is in the first intermediate signal and associated with an offset voltage of the first-stage amplifier, in order to obtain a second intermediate signal; a first chopper, having input terminals coupled to output terminals of the first high-pass filter circuit, and being configured to perform chopper modulation and demodulation on the second intermediate signal to obtain a third intermediate signal; and a second-stage amplifier, having input terminals coupled to output terminals of the first chopper, and being configured to amplify the third intermediate signal to generate an output signal.

A power amplifier circuit includes a differential amplifier circuit configured to amplify a radio-frequency signal, a transformer disposed on an output side with respect to the differential amplifier circuit and including a primary winding and a secondary winding, and a dispersion circuit coupled to a midpoint of the primary winding of the transformer and configured to operate as an adjustment circuit. The dispersion circuit is configured to adjust, based on a supply voltage controlled in accordance with the envelope of the radio-frequency signal, a bias (bias current or bias voltage) to be supplied to the differential amplifier circuit.

A power module includes: a first substrate having an outer surface and an inner surface, the first substrate extending from a first longitudinal end toward a second longitudinal end; a semiconductor die coupled to the inner surface of the first substrate; and a second substrate having an outer surface and an inner surface, the semiconductor die being coupled to the inner surface of the second substrate, the second substrate extending from a first longitudinal end toward a second longitudinal end, wherein the first longitudinal end of the first substrate is longitudinally offset from the first longitudinal end of the second substrate.

A system includes an inverter including: a first galvanic isolator separating a low voltage area from a high voltage area, the first galvanic isolator having a first galvanic isolator output path; a second galvanic isolator having a second galvanic isolator output path; an amplifier connected to the first galvanic isolator via the first galvanic isolator output path, and connected to the second galvanic isolator via the second galvanic isolator output path, the amplifier having a first amplifier output path and a second amplifier output path; a comparator connected to the amplifier via the first amplifier output path and the second amplifier output path, the comparator having a first comparator output path and a second comparator output path; and a pulse reshape and envelope detector connected to the comparator via the first comparator output path and the second comparator output path.

A system comprises an inverter configured to convert DC power from a battery to AC power to drive a motor, wherein the inverter includes: a galvanic isolator separating a high voltage area from a low voltage area; a low voltage phase controller in the low voltage area, the low voltage phase controller configured to receive a clock reference signal; and a high voltage phase controller in the high voltage area, the high voltage phase controller configured to align a clock reference signal of the high voltage phase controller with the clock reference signal of the low voltage phase controller.

A system includes: an inverter configured to convert DC power from a battery to AC power to drive a motor, wherein the inverter includes: a galvanic interface configured to separate a high voltage area from a low voltage area, the galvanic interface including a command channel and a message channel; a low voltage controller in the low voltage area, the low voltage controller configured to receive a PWM signal from a PWM controller; and a high voltage controller in the high voltage area, the high voltage controller configured to receive a control signal from the low voltage controller using the command channel of the galvanic interface, and send a switch state signal to the low voltage controller using the command channel of the galvanic interface, wherein the low voltage controller is configured to control the control signal based on the PWM signal and the switch state signal.

A power module includes: a first substrate having an outer surface and an inner surface, the first substrate extending from a first longitudinal end toward a second longitudinal end; a power switch including a semiconductor die, the power switch being coupled to the inner surface of the first substrate; a second substrate having an outer surface and an inner surface, the power switch being coupled to the inner surface of the second substrate, the second substrate extending from a first longitudinal end toward a second longitudinal end, wherein the first longitudinal end of the first substrate is longitudinally offset from the first longitudinal end of the second substrate; a first electrically conductive spacer coupled to inner surface of the first substrate and to the inner surface of the second substrate; and a flex circuit coupled to the power switch.