Direct current offset canceling circuit of trans-impedance amplifier and automatic gain control trans-impedance amplifier thereof
First Claim
1. A direct current (DC) offset canceling circuit of trans-impedance amplifier used for filtering a DC component of an input current, comprising:
- a trans-impedance amplifier having an input end and an output end, wherein the input end is used for receiving the input current, and converting the input current into a first voltage signal to be output by the output end, said trans-impedance amplifier comprising;
a plurality of inverters connected in series, wherein a sample node is defined between the inverters and at the input and output ends of the trans-impedance amplifier respectively; and
a resistor having one end connected to the input end, and the other end connected to the output end;
a DC detector for retrieving and comparing the signals at any sample node, thereby generating a trigger signal;
a DC eliminator connected to the input end of the trans-impedance amplifier, for providing a path to the DC component of the input current in response to the triggering by the trigger signal, to eliminate the DC component;
a reference voltage unit for outputting a reference voltage value; and
a voltage output amplifier for comparing the reference voltage and the first voltage signals, to amplify the output of a second voltage signal.
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Accused Products
Abstract
A direct current (DC) offset canceling circuit of a trans-impedance amplifier and an automatic gain control trans-impedance amplifier is provided, including: a trans-impedance amplifier for receiving an input current and converting the input current into a first voltage signal, while the trans-impedance amplifier is provided with a plurality of inverters connected in series, wherein a sample node is defined between each inverter; a DC detector for retrieving and comparing the signals at any sample node, thereby generating a trigger signal according to the comparison; a DC eliminator for providing a path to the DC component of the input current in response to the triggering by the signal trigger, to eliminate the DC component; a reference voltage unit for outputting a reference voltage value; and a voltage output amplifier for comparing the reference voltage and the first voltage signal, to amplify the output of a second voltage signal.
15 Citations
20 Claims
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1. A direct current (DC) offset canceling circuit of trans-impedance amplifier used for filtering a DC component of an input current, comprising:
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a trans-impedance amplifier having an input end and an output end, wherein the input end is used for receiving the input current, and converting the input current into a first voltage signal to be output by the output end, said trans-impedance amplifier comprising;
a plurality of inverters connected in series, wherein a sample node is defined between the inverters and at the input and output ends of the trans-impedance amplifier respectively; and
a resistor having one end connected to the input end, and the other end connected to the output end;
a DC detector for retrieving and comparing the signals at any sample node, thereby generating a trigger signal;
a DC eliminator connected to the input end of the trans-impedance amplifier, for providing a path to the DC component of the input current in response to the triggering by the trigger signal, to eliminate the DC component;
a reference voltage unit for outputting a reference voltage value; and
a voltage output amplifier for comparing the reference voltage and the first voltage signals, to amplify the output of a second voltage signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An automatic gain control trans-impedance amplifier, comprising:
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a trans-impedance amplifier having an input end and an output end, wherein the input end is used for receiving the input current, and converting the input current into a first voltage signal to be output by the output end, the trans-impedance amplifier comprising;
a plurality of inverters connected in series, wherein a sample node is defined between the inverters and at the input and output ends of the trans-impedance amplifier, respectively; and
a resistor having one end connected to the input end, and the other end connected to the output end;
a DC detector for retrieving and comparing the signals at any sample node, thereby generating a trigger signal;
a DC eliminator connected to the input end of the trans-impedance amplifier, for providing a path to the DC component of the input current in response to the triggering by the signal trigger, to eliminate the DC component;
a reference voltage unit for outputting a reference voltage value;
a voltage output amplifier for comparing the reference voltage and the first voltage signal, to amplify the output of a second voltage signal; and
a gain controller connected in parallel to a first inverter in the trans-impedance amplifier, for receiving the feedback trigger signal, to control the gain of the trans-impedance amplifier. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification