Current mirror circuit and receiver using the same
AssigneeMegaChips Corporation
InventorRyota Yamahana
Life of this patent
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Abstract
A current mirror circuit that amplifies a reference current generated by a current source at a first magnification to supply a mirror current to a load circuit. The current mirror circuit includes a first transistor and a second transistor that share a power supply, and a drain potential mirror unit that amplifies the reference current at a second magnification to generate a first current, that amplifies a generated first current at a third magnification to generate a second current, and that supplies a predetermined potential determined based on the second current to a drain of the second transistor. The mirror current is supplied from the second transistor to the load circuit based on a potential of a gate of the first transistor determined based on the reference current.
Claims20
A current mirror circuit comprising:
- a first transistor and a second transistor which share a power supply;
- and
- a drain potential mirror unit that determines a predetermined potential of a drain of the second transistor such that the predetermined potential is equal to a potential of a drain of the first transistor determined based on a reference current generated by a current source,
- wherein the second transistor supplies a mirror current to a load circuit based on the predetermined potential of the drain of the second transistor and the potential of the drain of the first transistor, and
- wherein a drain potential mirror unit that amplifies the reference current generated by a current source at a first magnification to generate a first current, amplifies the generated first current at a second magnification to generate a second current, and determines the predetermined potential of the drain of the second transistor based on the second current.
A receiver that measures a strength of an optical signal output from a transmitter, the receiver comprising:
- a photodetector that generates a reference current based on the optical signal;
- a current mirror circuit that amplifies the reference current at a predetermined magnification to generate a mirror current;
- a current mode AD converter that converts the mirror current to a digital voltage signal at a predetermined conversion rate;
- and
- a logic unit that measures the strength of the optical signal indicated by the digital voltage signal,
- wherein the current mirror circuit comprises:
- a first transistor and a second transistor which share a power supply;
- and
- a drain potential mirror unit that determines a predetermined potential of a drain of the second transistor such that the predetermined potential is equal to a potential of a drain of the first transistor determined based on a reference current generated by a current source,
- wherein the second transistor supplies the mirror current to the current mode AD converter based on the potential of the drain of the first transistor determined based on the reference current.
Dependencies are inferred from the claim text.