A driver for power tube grid of class-d audio power amplifier

Abstract

The invention discloses a driver for a power tube grid of a Class D audio power amplifier. The power tube grid is driven by means of complementary current sources. The driver can ensure that the capability of driving the grid of a power tube is consistent so as to ensure that the variation rate of output pulse signals is consistent no matter the output current is high, low, positive or negative. Thus, the driver ensures lower electromagnetic interference and can reduce the errors caused by higher variation rate of output signals, and the aim of reducing the total harmonic distortion as much as possible while reducing the electromagnetic interference is achieved.

Description

technical field [0001] The invention relates to a driver for a power tube grid, in particular to a driver for a power tube grid of a class D audio power amplifier. Background technique [0002] Class D amplifiers have considerable advantages in terms of power efficiency compared to linear audio amplifiers such as Class A, Class B, and Class AB. For linear amplifiers such as Class AB, the bias components and linear operation of the output transistors dissipate significant power. And because the power output stage of the class D audio power amplifier adopts the switching mode to control the direction of the current flowing through the load, so the static power consumption is very small, and higher efficiency can be achieved. The power consumption of the amplifier is mainly dissipated in the form of heat, so the requirements for heat dissipation of the class D amplifier are greatly reduced. battery life. Class D audio power amplifiers are ideal for compact, high-power applic...

AI Technical Summary

Problems solved by technology

The output current of the MOS current source changes with the change of its output level, and the output terminal of the MOS current source is connected to the gate of the power tube. Therefore, the current of the MOS current source changes with the change of the current, resulting in an increase of the output signal , the rate of decline varies greatly

If the rising and falling speeds are too high, strong electromagnetic interference may be generated; if the rising and falling speeds are too small, the output audio signal will be lost too much, resulting in a large total harmonic distortion

[0007] 2. The rising and falling speed of the output signal varies greatly with the polarity of the load current

The rise and fall rate of the output audio signal generated by the existing drive circuit is asymmetrical, which not only leads to a large total harmonic distortion of the output signal but also makes the electromagnetic interference increase with the increase of the rate

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