| 摘要 |
<p>The present invention relates to an apparatus to control the output limit of a digital amplifier and, more specifically, to an apparatus to control the output limit of a digital amplifier in a fixed frequency method in order to secure the stability of the digital amplifier by limiting the output frequency of the digital amp by controlling an input signal having a high frequency which deviates from an audible frequency range, and an input signal of an overvoltage signal. The most structural problems of a digital amplifier in an existing PWM method are able to cause: damage of an FET by exceeding the current of the FET since a big signal suddenly comes in if an excessive input enters by the generation of the excessive input; not only noise which makes people feel uncomfortable by an output signal itself by being clipped if a voltage applied on the FET approaches, but also damages a speaker by the clipping action; and damages the digital amplifier by a resonance phenomenon of the digital amplifier by a delay output of a high frequency band. The present invention controls and manages a signal inputted to the FET before the signal is applied on the FET in case an abnormal input signal is inputted such as a case wherein a frequency, which deviates from the audible frequency range, comes in or an overvoltage is inputted. The present invention provides a control device to limit the output of a digital amplifier in the fixed frequency method in accordance to an input signal of the digital amplifier in order to secure the stability of the digital amplifier by preventing an abnormal input signal in advance before passing an FET or an inductor.</p> |
