Electronic system auto-mute control circuit and control method thereof
AssigneeAnpec Electronics Corporation
InventorMing-Huang Chang
Life of this patent
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Abstract
An auto-mute control circuit is disclosed. The auto-mute control circuit includes an analog amplifier, a detecting circuit and a direct-current (DC) level adjusting circuit. The analog amplifier receives an input signal and outputs a sensing voltage signal accordingly. The detecting circuit compares a common-mode voltage received with the sensing voltage signal received and outputs a comparison signal accordingly. The DC adjusting circuit receives the comparison signal and outputs an Up-Down digital signal, a fine tune digital signal and a rough tune digital signal, so that a sensing DC level is equal to the common-mode voltage.
Claims15
An auto-mute control circuit, comprising:
- an analog amplifier, receiving an input signal and outputting a sensing voltage signal accordingly;
- a detecting circuit, coupled to the analog amplifier, wherein the detecting circuit compares a common-mode voltage received with the sensing voltage signal received and outputs a comparison signal according to a comparing result;
- and
- a direct-current (DC) level adjusting circuit, receiving the comparison signal and accordingly outputting an Up-Down digital signal, a fine tune digital signal and a rough tune digital signal to the analog amplifier to adjust a sensing DC level of the sensing voltage signal, so that the sensing DC level is close to or equal to the common-mode voltage, wherein initial values of the fine tune digital signal and the rough tune digital signal are both “zero”;
- wherein when the sensing DC level unadjusted is lower than the common-mode voltage, the DC level adjusting circuit sets total bit values of the fine tune digital signal as “one” and outputs the Up-Down digital signal of a high level voltage to the analog amplifier to increase the sensing DC level;
- when the sensing DC level unadjusted is higher than the common-mode voltage, the DC level adjusting circuit sets the total bit values of the fine tune digital signal as “one” and outputs the Up-Down digital signal of a low level voltage to the analog amplifier to decrease the sensing DC level.
Dependencies are inferred from the claim text.