Current mirror arrangement
First Claim
1. A current-source arrangement comprising, a first current circuit coupled between a first terminal and a common terminal, said first circuit comprising at least the main current path of a first semiconductor device connected in series with a first resistor, a second current circuit coupled between a second terminal and the common terminal, said second current circuit comprising at least the main current path of a semiconductor device and a second resistor, the two semiconductor devices being connected in parallel with respect to their drives, an active negative feedback circuit having a differential input and an output, means coupling said differential input between the ends of the first and the second resistor which are remote from the common terminal, and means coupling said output to the second current circuit to provide negative feedback so as to counteract a variation of the voltage across the second resistor relative to the voltage across the first resistor.
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Accused Products
Abstract
A current source arrangement which may be constituted by a current mirror or by a multiple current source, having a first current circuit and a second current circuit, each equipped with a semiconductor device in series with a resistor. For the purpose of noise reduction the difference between the voltages across the two resistors is negatively fed back to the second current circuit.
49 Citations
19 Claims
- 1. A current-source arrangement comprising, a first current circuit coupled between a first terminal and a common terminal, said first circuit comprising at least the main current path of a first semiconductor device connected in series with a first resistor, a second current circuit coupled between a second terminal and the common terminal, said second current circuit comprising at least the main current path of a semiconductor device and a second resistor, the two semiconductor devices being connected in parallel with respect to their drives, an active negative feedback circuit having a differential input and an output, means coupling said differential input between the ends of the first and the second resistor which are remote from the common terminal, and means coupling said output to the second current circuit to provide negative feedback so as to counteract a variation of the voltage across the second resistor relative to the voltage across the first resistor.
- 8. A circuit arrangement comprising, a first series circuit including a first semiconductor device and a first resistor coupled between a first terminal and a common terminal, a second series circuit including a second semiconductor device having a control electrode coupled to the first terminal and a second resistor, means coupling said second series circuit between a second terminal and said common terminal, whereby first and second currents are caused to flow in said first and second series circuits, respectively, via said first and second terminals, respectively, in a fixed relationship to one another, a negative feedback circuit including an amplifier with first and second input terminals coupled to corresponding circuit points in said first and second series circuits, respectively, and an output coupled only to a circuit point in the second series circuit to provide a negative feedback signal thereby to reduce the circuit noise inherent in the circuit arrangement.
- 10. A current mirror comprising, an input terminal, an output terminal, a common terminal, first and second resistors, means connecting a first semiconductor device in a first series circuit with said first resistor between the input terminal and the common terminal, a second semiconductor device having a control electrode, means connecting the second semiconductor device in a second series circuit with said second resistor between the output terminal and the common terminal and with said control electrode coupled to said input terminal, thereby to derive a current at the output terminal having a given relationship to a current at the input terminal, and a negative feedback amplifier having first and second inputs coupled to corresponding first and second circuit points in the first and second series circuits, respectively, and an output coupled to a terminal of the second semiconductor device other than the control electrode so as to provide a negative feedback.
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17. A current source arrangement comprising, a first current circuit including a first semiconductor device and a first resistor connected in a first series circuit between a first terminal and a common terminal, a second current circuit including a second semiconductor device and a second resistor connected in a second series circuit between a second terminal and the common terminal, means coupling said first and second current circuits so as derive a current at the second terminal that bears a fixed relationship to a current at the first terminal, and a negative feedback amplifier circuit having a differential input coupled to corresponding circuit points in the first and second current circuits and an output coupled to a circuit point in the second current circuit to supply a current to said second current circuit that provides a negative feedback exclusively to second current circuit.
- 18. A current source arrangement comprising a semiconductor substrate on which are formed first and second insulated gate field effect transistors with interconnected gate electrodes, means connecting the first transistor in a first series circuit with a first resistor between a first terminal and a common terminal, means connecting said second transistor in a second series circuit with a second resistor between a second terminal and the common terminal, the first FET having its drain and gate electrodes interconnected to form a diode and having a second gate terminal coupled to said substrate in an area adjacent to the first FET to form therewith a junction FET in parallel with the first FET, said second gate terminal being connected to the source electrode of the second FET to form an active negative feedback circuit from which a current is supplied to the second resistor in a sense to counteract a variation of voltage across the second resistor relative to the voltage across the first resistor.
Specification