Preamplifying circuit
AssigneeSuzhou Novosense Microelectronics Co., Ltd.
InventorQihui Chen
Life of this patent
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Abstract
Provided is a preamplifying circuit, including a first amplifier and a second amplifier sequentially connected in series, wherein an output end of the second amplifier is connected to a circuit output end, and an input end of the first amplifier is connected to a circuit input end. The preamplifying circuit further includes a positive feedback branch including a diode group and a third amplifier, wherein one end of the diode group is connected to the input end of the first amplifier. The positive feedback circuit can positively feed part of signals back to the other end of the diode group, so that voltage drops at two ends of the diode group can be reduced, and harmonic distortion caused by nonlinearity of the diode group is reduced. Thus, the sound quality detected by a microphone sensor is improved.
Claims9
A preamplifying circuit, comprising a first amplifier and a second amplifier sequentially connected in series, wherein an output end of the second amplifier is connected to a circuit output end;
- an input end of the first amplifier is connected to a circuit input end;
- the preamplifying circuit being characterized by further comprising a positive feedback branch which comprises a diode group and a third amplifier, wherein one end of the diode group is connected to the input end of the first amplifier;
- an input end of the third amplifier is connected between the first amplifier and the second amplifier;
- an output end of the third amplifier is connected to the other end of the diode group;
- and the diode group comprises a first diode and a second diode that are in inverse parallel connection;
- wherein the positive feedback branch further comprises a first capacitor, which is connected between the input end of the third amplifier and the output end of the first amplifier, and a second capacitor which is connected between the input end of the third amplifier and the ground.
Dependencies are inferred from the claim text.