According to one embodiment, a class-D amplifier including: a PWM modulator that outputs a PWM modulation signal in response to an input signal; and a drive circuit that amplifies the PWM modulation signal, and supplies it to an output end. The drive circuit includes: a first output transistor whose main current path is connected between a power source supplying end and the output end; a second output transistor having a size larger than a size of the first output transistor; and a resistance element that is connected between the main current path of the first output transistor and the output end.

An envelope tracking power management circuit is disclosed. An envelope tracking power management circuit includes a first envelope tracking amplifier(s) and a second envelope tracking amplifier(s), each configured to amplify a respective radio frequency (RF) signal(s) based on a respective supply voltage. A power management circuit can determine that a selected envelope tracking amplifier, which can be either the first envelope tracking amplifier(s) or the second envelope tracking amplifier(s), receives the respective supply voltage lower than a voltage required to amplify the respective RF signal(s) to a predetermined voltage. In response, the power management circuit provides a boosted voltage, which is no less than the required voltage, to the selected envelope tracking amplifier. As such, it is possible to enable the selected envelope tracking amplifier to amplify the respective RF signal(s) to the predetermined voltage without increasing cost, footprint, and power consumption of the envelope tracking power management circuit.

Various implementations include a common mode voltage controller for a self-boosting push pull amplifier. In some implementations, input signal are processed by: calculating, based upon the input signal, a maximum duty cycle to achieve a target differential in an output of the self-boosting push pull amplifier; calculating, based on the input signal, a set of control parameters associated with adjusting a common mode voltage of the output; and generating, based on the input signal, a pair of signals configured to adjust the common mode voltage of the output, wherein the pair of signals include a gain adjustment and offset based on the maximum duty cycle and the set of control parameters, and wherein the pair of signals are configured to maintain the target differential in the output of the self-boosting push pull amplifier as the common mode voltage is adjusted to a different operating point.

A switching system is connected to the power amplifier of an RF system. The switching system can switch the DC supply voltage to the power amplifier while handling the high DC current and the nanosecond switching speed requirements that are mandatory for most RF systems. The embodiments can rapidly control DC voltages but not interfere with the optimized operation of the RF transistor. The embodiments provide a desired sharp turn-on leading edge for an RF pulse while eliminating the extremely long and undesirable ramp down that typically occurs beyond the desired RF pulse period.

A power converter converts a digital input signal into an RF output power signal. A digital signal processor converts the input signal into one or more copies of a multi-bit RF signal. Each copy of the multi-bit RF signal is applied to a corresponding multi-bit current generator having a set of weighted, switched current sources, each of which is controlled by a different bit of the multi-bit RF signal. The currents from the different current sources are processed and combined to generate the output power signal.

Aspects of the present disclosure provide a high voltage switch with a fast turn-off. An example power supply circuit generally includes a capacitive element for coupling to a power terminal of an amplifier, a first switch configured to be closed in a first mode and to be open in a second mode, a second switch coupled in series between the first switch and the capacitive element and configured to be closed in the first mode and to be open in the second mode, a first circuit coupled to the first switch and configured to charge the capacitive element and power the amplifier in the first mode, and a buffer circuit having an output coupled to a first node and configured to output a first voltage level greater than half of a second voltage level at a second node.

The present invention relates to a multiple output boost DC-DC power converter generating two, three or more separate DC output voltages, and to a multi-level power inverter and an alternating current generator both employing the multiple output boost DC-DC power converter.

An envelope tracking power supply, which includes a parallel amplifier, switching circuitry, and a parallel switching supply, is disclosed. The envelope tracking power supply provides an envelope power supply signal to a load. The parallel amplifier regulates an envelope power supply voltage of the envelope power supply signal based on a setpoint of the envelope power supply voltage. The switching circuitry at least partially provides the envelope power supply signal via a first inductive element and drives an output current from the parallel amplifier toward zero. The parallel switching supply provides an assist current to further drive the output current from the parallel amplifier toward zero based on an estimate of a current in the first inductive element and an estimate of a current in the load.

An amplifier circuit includes a differential input terminal, a first power supplier, an amplifier, and a current redistributor. A differential input terminal includes a first differential pair of a p-type and a second differential pair of an n-type, and receives an input voltage. A first power supplier supplies a bias current to the differential input terminal. An amplifier receives an output current of the first differential pair and an output current of the second differential pair, and applies an amplified current to an output node. A current redistributor receives the output current of the first differential pair and the output current of the second differential pair, and provides a redistribution current to the differential input terminal.

An amplifier may include control circuitry that may track a first input signal parameter and, in response, adjust a value of a second input parameter. Input parameter tracking and adjustment may facilitate control of output parameters for the amplifier. For example, an envelope-tracking amplifier may track input signal amplitude and adjust other input parameters in response. The adjustments may facilitate control of output parameters, such as gain or efficiency. The amplifier may further include calibration circuitry to determine adjustment responses to various tracked input parameters.