Patent ID: 7816990
Filing Date: 2010-10-19
Classification: H03G,H03H,H04N

Abstract:
1. A variable gain amplification circuit comprising: a gain-variable signal generator comprising a variable resistor and an output terminal, said variable resistor comprising a plurality of selectable resistors, wherein a resistance value of said variable resistor is controlled by controlling a first switching unit so as to select a resistor of said plurality of selectable resistors; a variable capacitor connected between said output terminal and an AC grounded terminal, said variable capacitor comprising a plurality of selectable capacitors, wherein a capacitance value of said variable capacitor is controlled by controlling a second switching unit so as to select a capacitor of said plurality of selectable capacitors; and a control circuit operable to control said first switching unit and said second switching unit so as to control the capacitance value of said variable capacitor and the resistance value of said variable resistor, wherein said control circuit controls the capacitance value of said variable capacitor by controlling on/off action of said first switching unit according to the resistance value of said variable resistor.