Abstract: A buffer circuit includes an input terminal configured to receive an input signal, an output terminal, an inverter, and a resistor-capacitor (RC) circuit coupled in series with the inverter between the input terminal and the output terminal. The RC circuit includes an NMOS transistor coupled between an RC circuit output terminal and a reference node, a resistor coupled between the RC circuit output terminal and a power supply node, and a capacitor coupled between the RC circuit output terminal and one of the power supply node or the reference node, and the inverter and the RC circuit are configured to generate an output signal at the output terminal based on the input signal.

Abstract: An equalizer for equalizing an input signal includes an infinitive impulse response (IIR) filtering portion for filtering the input signal to produce N filtered outputs; a gain-adjusting portion coupled to the IIR filtering portion with N gains for adjusting the N filtered outputs to produce N gained outputs, respectively; and an adder for summing the N gained outputs to generate an equalized output signal. N is an integer larger than 2.

Abstract: An audio volume control circuit includes a signal intensity calculating circuit for generating a first signal intensity value corresponding to a signal intensity corresponding to an audio channel data; a low-pass filter for filtering the first signal intensity to generate a second signal intensity value; an averaging unit for averaging the second signal intensity value and previous M?1 second signal intensity values to obtain a third signal intensity value, with M being a natural number greater than 1; a gain calculating circuit for obtaining an original gain value according to the third signal intensity value with reference to the adjustment condition; a buffer for temporarily storing the audio channel data; and an audio volume adjusting circuit for generating an adjustment gain value according to the original gain value to adjust the audio channel data stored in the buffer.

Abstract: An audio volume control circuit includes a signal intensity calculating circuit for generating a first signal intensity value corresponding to a signal intensity corresponding to an audio channel data; a low-pass filter for filtering the first signal intensity to generate a second signal intensity value; an averaging unit for averaging the second signal intensity value and previous M?1 second signal intensity values to obtain a third signal intensity value, with M being a natural number greater than 1; a gain calculating circuit for obtaining an original gain value according to the third signal intensity value with reference to the adjustment condition; a buffer for temporarily storing the audio channel data; and an audio volume adjusting circuit for generating an adjustment gain value according to the original gain value to adjust the audio channel data stored in the buffer.

Abstract: An equalizer for equalizing an input signal includes an infinitive impulse response (IIR) filtering portion for filtering the input signal to produce N filtered outputs; a gain-adjusting portion coupled to the IIR filtering portion with N gains for adjusting the N filtered outputs to produce N gained outputs, respectively; and an adder for summing the N gained outputs to generate an equalized output signal. N is an integer larger than 2.