METHOD OF PREVENTING POP-UP NOISE AND DIGITAL AMPLIFIER INCLUDING POP-UP NOISE PREVENTION CIRCUIT

摘要

A method of preventing pop-up noise and a digital amplifier including a pop-up noise prevention circuit are provided to remove pop-up noise when a power supply voltage of the digital amplifier is supplied or cut off, by controlling floating timing when a reference node becomes in a high-impedance state. According to a method of preventing pop-up noise, a power supply voltage is supplied to a digital amplifier in order to apply a differential voltage between an output node and a reference node to an output load(S10). A DC voltage is applied to the output node(S20). A reference voltage corresponding to the DC voltage is outputted to the reference node(S30). Floating timing of the reference node is controlled(S40). During the step of controlling floating timing of the reference node, the reference node is floated to a high-impedance state before the DC voltage is applied to the output node. After delay time required for stabilizing a voltage of the output node to the DC voltage has elapsed, the high-impedance state of the reference node is released.