Temperature compensation circuits and methods for adjusting one or more circuit parameters of a power amplifier (PA) to maintain approximately constant Gain versus time during pulsed operation sufficient to substantially offset self-heating of the PA. Some embodiments compensate for PA Gain droop due to self-heating using a Sample and Hold (S&H) circuit. The S&H circuit samples and holds an initial temperature of the PA at commencement of a pulse. Thereafter, the S&H circuit generates a continuous measurement that corresponds to the temperature of the PA during the remainder of the pulse. A Gain Control signal is generated that is a function of the difference between the initial temperature and the operating temperature of the PA as the PA self-heats for the duration of the pulse. The Gain Control signal is applied to one or more adjustable or tunable circuits within a PA to offset the Gain droop of the PA.

A power amplifier module that includes a power amplifier and a controller is presented herein. The power amplifier module may include a set of transistor stages and a plurality of bias circuits. At least one transistor stage from the set of transistor stages may be in electrical communication with a first bias circuit and a second bias circuit from the plurality of bias circuits. The first bias circuit can be configured to apply a first bias voltage to the at least one transistor stage and the second bias circuit can be configured to apply a second bias voltage to the at least one transistor stage. The controller may be configured to activate one of the first bias circuit and the second bias circuit.

A regenerative current detection circuit includes a first power MOS transistor that is configured as a current mirror to a second power MOS transistor connected to drive a motor winding, a first feedback amplifier that compares a first regenerative current that flows in the first power MOS transistor with a second regenerative current that flows in the second power MOS transistor and outputs a comparison result, the first regenerative current being obtained by multiplying the second regenerative current by a current mirror ratio, and a current detection circuit that outputs a detection current based on the comparison result.

A pulse detector amplifier is disclosed. The pulse detector amplifier may have a detection switching leg that receives an input energy pulse. The pulse detector may have a mirror fast trigger including a trigger node and controlling a mirrored switching leg. The detection switching leg may trigger the trigger node in response to the input energy pulse. The pulse detector amplifier may also have a mirrored switching leg that controlled by the trigger node. The mirrored switching leg may control a voltage and/or current on the output node responsive to the input energy pulse. Thus, the pulse detector may generally include a cascode architecture, with a mirror fast trigger (which may include a FET) between the mirrored legs of the amplifier and enhancing the rapid triggering of the amplifier output. Thus the pulse detector may be power efficient, may have a small part count, and may be sensitive.

Certain aspects of the present disclosure generally relate to a low voltage, accurate current mirror, which may be used for distributed sensing of a remote current in an integrated circuit (IC). One example current mirror typically includes a first pair of transistors, a second pair of transistors in cascode with the first pair of transistors, a switching network coupled to the second pair of transistors, and a third pair of transistors coupled to the switching network. An input node between the first and second pairs of transistors may be configured to receive an input current for the current mirror, and an output node at the first pair of transistors may be configured to sink an output current for the current mirror, proportional to the input current. This current mirror architecture offers a hybrid low-voltage/high-voltage solution, tolerates low input voltages, provides high output impedance, and offers low area and power consumption.

A multi-stage amplifier, comprising a first amplifier stage is presented. The output of the first amplifier stage is coupled to a first terminal of a capacitor having a controllable capacitance. The input of a second amplifier stage is coupled to the output of the first amplifier stage and the first terminal of the capacitor. The output of the second amplifier stage is coupled to a second terminal of the capacitor and an output of the multi-stage amplifier. The input of a current sensing circuit is coupled with the output of the multi-stage amplifier. A control signal generator is coupled between the output of the current sensing circuit and a control terminal of the capacitor. The control signal generator provides a control signal to the capacitor in order to control or vary the capacitance of the capacitor.

A power amplifier module that includes a power amplifier and a controller is presented herein. The power amplifier module may include a set of transistor stages and a plurality of bias circuits. At least one transistor stage from the set of transistor stages may be in electrical communication with a first bias circuit and a second bias circuit from the plurality of bias circuits. The first bias circuit can be configured to apply a first bias voltage to the at least one transistor stage and the second bias circuit can be configured to apply a second bias voltage to the at least one transistor stage. The controller may be configured to activate one of the first bias circuit and the second bias circuit.

A self-biasing output booster amplifier having an input amplifier stage, an output amplifier stage being operatively connected to an output of the input amplifier stage, and first and second current copying circuits. The second current copying circuit is biased from an output of the self-biasing output booster amplifier. The first and second current copying circuits are configured to copy at least a portion of the current through the output amplifier stage. The sum of the output of the second current copying circuit and the output of the output amplifier stage provides the output current of the self-biasing output booster amplifier, Finally, the input amplifier stage is biased from the output of the second current copying.

In an audio amplifier circuit, a power supply terminal receives a power supply voltage. A voltage source generates an internal power supply voltage obtained by multiplying the power supply voltage by a first gain and a bias voltage obtained by multiplying the power supply voltage by a second gain. An input gain circuit amplifies an analog audio signal with reference to the bias voltage. The input gain circuit has an input stage and a gain stage. A phase compensation capacitor is connected to the gain stage. A withstand voltage protection circuit clamps an output voltage of the gain stage to a predetermined clamp voltage.

A system for measuring high power currents, including: a low power transistor that is a scaled replica of a high power transistor of a high power driver; a regulator connected to the low power transistor, wherein the regulator is configured to regulate the current flowing through the low power transistor based upon a voltage sensed across the high power transistor and a chop signal; a current mirror with an input connected to the regulator and an output; a current detector having in input configured to receive the chop signal, wherein the current detector is connected to the output of the current mirror and wherein the current detector is configured to measure the current at the output of the current mirror to produce an estimate of the current flowing through the high power transistor.