Power amplifier circuit powered by single power supply based on MOS transistor

Abstract

The invention discloses a power amplifier circuit powered by a single power supply based on an MOS transistor. The circuit comprises a power amplification circuit and an intermediate amplifier. The power amplification circuit is electrically connected with the intermediate amplifier, the power amplification circuit comprises a positive half-cycle power amplification circuit, a negative half-cyclepower amplification circuit and an impedance matching output transformer, and a class B single-power-supply transformer coupling push-pull power analog linear amplification circuit is formed by connecting power MOS single tubes or multiple tubes with the same characteristics in parallel; the intermediate amplifier comprises an output feedback detection circuit, a proportional integral differentiating circuit, a positive and negative half-cycle balance and crossover distortion correction circuit and a protected positive and negative half-cycle voltage follower circuit. The power amplifier circuit is directly installed in a power amplifier, a voltage type MOS tube is adopted as a power tube, a front end circuit is simple and reliable, universality is large, the size is small, reliability ishigh, power matching is simple, and the power amplifier circuit is particularly suitable for a broadcast power amplifier machine requiring alternating current and direct current, and full-power outputthe same as that of alternating current power supply is kept during direct current power supply.

Description

technical field [0001] The invention relates to the field of power amplifier circuits, in particular to a power amplifier circuit powered by a single power supply based on a MOS tube. Background technique [0002] At present, in ordinary class AB power amplifier circuits, the most commonly used power tube is a current-type power triode, which is usually used in pairs of NPN and PNP, and uses + / - dual power supply for power supply. For some applications that require DC power supply (such as fire emergency broadcasting Power amplifier, etc.), one is a built-in DC / DC conversion circuit, which converts a single DC power supply into a dual power supply, the DC power supply efficiency is low, the circuit is complicated, and the reliability is not high; the other is an external DC / AC inverter, which converts the DC After turning into alternating current, the power amplifier is powered, but the installation is inconvenient and the cost is high. [0003] In order to solve the above ...

AI Technical Summary

Problems solved by technology

[0002] At present, in ordinary class AB power amplifier circuits, the most commonly used power tube is a current-type power triode, which is usually used in pairs of NPN and PNP, and uses + / - dual power supply for power supply. For some applications that require DC power supply (such as fire emergency broadcasting Power amplifier, etc.), one is a built-in DC / DC conversion circuit, which converts a single DC power supply into a dual power supply, the DC power supply efficiency is low, the circuit is complicated, and the reliability is not high; the other is an external DC / AC inverter, which converts the DC After turning into alternating current, it supplies power to the power amplifier, but the installation is inconvenient and the cost is high

[0003] In order to solve the above shortcomings, the existing technology proposes to use the coupling drive transformer to output the driving signal of positive and negative half cycles alternately to the power transistor, and the power transistor drives the push-pull output transformer powered by a single power supply for power amplification. Due to the driving capability of the coupling drive transformer As well as the limitation of the maximum current of the power transistor, low DC voltage power supply cannot be achieved and high power output is required, and the structure is complex and the cost is high. The power MOS tubes used in the existing push-pull power supply circuits all work in switch mode , cannot directly transplant the circuit to the analog audio amplifier circuit

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