Variable gain amplifier
First Claim
1. A variable gain amplifier, comprising a fitted differential module group and an offset voltage output module, wherein:
- the fitted differential module group is configured to output, under control of a driving voltage and offset voltages, an output current of the variable gain amplifier according to a reference current;
the fitted differential module group includes a number n fitted differential modules, and the number n is any positive integer larger than 1; and
the n fitted differential modules are cascaded in turn and meet the following;
Iout(s−
1)=Iin(s),wherein s is larger than 1 and smaller than or equal to the number n, Iout(s−
1) indicates an output current of an (s−
1)th fitted differential module, Iin(s) indicates an input current of an sth fitted differential module, an input current Iin(1) of a first fitted differential module of the fitted differential module group is the reference current, and an output current of an nth fitted differential module of the fitted differential module group is the output current of the variable gain amplifier; and
the offset voltage output module is configured to input the offset voltages, to the multiple fitted differential modules, respectively, wherein the offset voltages meet;
V2−
V1= . . . =Vs−
Vs-1 . . . =Vn−
Vn-1,wherein Vs indicates an offset voltage that the offset voltage output module inputs to the sth fitted differential module.
1 Assignment
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Accused Products
Abstract
The embodiments of the present invention disclose a variable gain amplifier and relate to the field of electronic circuits. The linear-in-dB relationship between an output current and a control voltage of the variable gain amplifier is relatively ideal. The variable gain amplifier includes a fitted differential module group and an offset voltage output module, where the fitted differential module group is configured to output, under the control of a driving voltage and offset voltages, an output current of the variable gain amplifier according to a reference current; and the fitted differential module group includes n fitted differential modules, the n fitted differential modules are cascaded in turn, and n is any positive integer larger than 1.
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Citations
6 Claims
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1. A variable gain amplifier, comprising a fitted differential module group and an offset voltage output module, wherein:
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the fitted differential module group is configured to output, under control of a driving voltage and offset voltages, an output current of the variable gain amplifier according to a reference current;
the fitted differential module group includes a number n fitted differential modules, and the number n is any positive integer larger than 1; and
the n fitted differential modules are cascaded in turn and meet the following;
Iout(s−
1)=Iin(s),wherein s is larger than 1 and smaller than or equal to the number n, Iout(s−
1) indicates an output current of an (s−
1)th fitted differential module, Iin(s) indicates an input current of an sth fitted differential module, an input current Iin(1) of a first fitted differential module of the fitted differential module group is the reference current, and an output current of an nth fitted differential module of the fitted differential module group is the output current of the variable gain amplifier; andthe offset voltage output module is configured to input the offset voltages, to the multiple fitted differential modules, respectively, wherein the offset voltages meet;
V2−
V1= . . . =Vs−
Vs-1 . . . =Vn−
Vn-1,wherein Vs indicates an offset voltage that the offset voltage output module inputs to the sth fitted differential module. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification