A kind of over-current protection method for class-d power amplifier chip

Abstract

The invention discloses an overcurrent protection method for D type power amplification chips in the integrated circuit field. The overcurrent protection method comprises a full-amplitude modulation step, a full-amplitude pulse signal outputting step, a judging step, a wave filtering step, a resetting step and a time delay step, wherein the full-amplitude modulation step comprises: receiving an audio frequency input signal input from outside to perform full-amplitude modulation, and continuously outputting a first full-amplitude PWM (Pulse-Width Modulation) signal and a second full-amplitude PWM signal having opposite phases; in the full-amplitude pulse signal outputting step, a load continuously outputs a full-amplitude pulse signal; in the judging step, an overcurrent signal is generated if the high potential level of the full-amplitude pulse signal is lower than an overcurrent threshold b, and the wave filtering step is performed; and in the resetting step, the load outputs no full-amplitude pulse signal. The overcurrent protection method has the technical effects of guaranteeing the high potential pulse width of the overcurrent signal to be larger than a wave filtering threshold a, preventing the overcurrent signal from being performed with pulse width filtering in the wave filtering step by mistake and effectively preventing the D type power amplification chips from being burnt.

Description

Technical field [0001] The invention relates to an overcurrent protection method for a class D power amplifier chip in the field of integrated circuits. Background technique [0002] See figure 1 , When the class D power amplifier chip is in the working state, once overcurrent occurs, that is, when the high potential level of the pulse signal output by the load on the class D power amplifier chip is lower than the overcurrent threshold b, the first output on the class D power amplifier chip The drive and the second output drive can be turned off immediately, the first power tube on the first output drive and the second power tube on the second output drive are also turned off accordingly, and the PWM modulation module keeps working . The overcurrent threshold b is preset. At this time, the class D power amplifier chip enters the overcurrent protection state. In the overcurrent protection state, the existing overcurrent protection method for the class D power amplifier chip incl...

AI Technical Summary

Problems solved by technology

[0011] The object of the present invention is an overcurrent protection method for class D power amplifier chips, which can solve the problem that the overcurrent signal is filtered by the wrong pulse width in the filtering step, resulting in the inability to carry out subsequent recovery steps and delay steps, and repeated impacts of large currents The first output driver and the second output driver on the class D power amplifier chip lead to a technical problem that the class D power amplifier chip is burned

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