CMOS current amplifier
AssigneeValorbec, Limited Partnership
InventorChunyan Wang
Life of this patent
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Abstract
This invention relates to a method and apparatus for amplifying an input current into an output current. An input current is first injected in or pulled out of a transimpedance stage and converted, in a linear way, into an interstage voltage. The interstage voltage is then converted into the output current. The conversion of the interstage voltage into an output current is performed by maintaining a transistor in the triode mode to obtain a linear conversion as well as adding a current which comes from a current source.
Claims13
A circuit for converting a time-variable voltage signal into a time-variable current signal, said circuit comprising:
- a first transistor for receiving said time-variable voltage signal and providing a shifted time-variable voltage signal;
- a second transistor which is maintained in a linear current-voltage operating zone, said second transistor receiving said shifted time-variable voltage signal and providing an intermediary time-variable current signal, said intermediary time-variable current signal being proportional to said time-variable voltage signal;
- a substantially fixed current source;
- an output, said output receiving a substantially fixed current signal from said substantially fixed current source and said intermediary time-variable current signal to provide a time-variable current signal.
A method for converting a time-variable voltage signal into an output time-variable current signal, said method comprising the steps of:
- providing a substantially fixed current signal generated by a substantially fixed current source;
- providing a resistance in a path between said current source and a reference;
- shifting said time-variable voltage signal onto said path between said current source and said resistance to generate a time-variable current signal flowing through said resistance;
- and
- adding said time-variable current signal and said substantially fixed current signal to provide said output time-variable current signal.
A method for amplifying an input time-variable current signal into an output time-variable current signal using at least one transistor, said method comprising the steps of:
- receiving said input time-variable current signal;
- converting said input time-variable current signal into an interstage time-variable voltage signal;
- providing a substantially fixed current signal generated by a substantially fixed current source;
- providing a resistance in a path between said current source and a reference;
- shifting said time-variable voltage signal onto said path between said current source and said resistance to generate a time-variable current signal flowing through said resistance;
- and
- adding said time-variable current signal and said substantially fixed current signal to provide said output time-variable current signal.
Dependencies are inferred from the claim text.