Ring oscillator
First Claim
1. A ring oscillator comprising, a plurality of cascaded inverting stages, each stage comprising an input circuit for detecting an output voltage of a preceding stage, characterized in that at least one inverting stage further comprises an output circuit having a current source that is controlled by said input circuit for supplying an output current to an input circuit of a succeeding stage.
1 Assignment
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Accused Products
Abstract
A ring oscillator circuit comprises a plurality of inverter states (301, 302, 303) connected in a series loop. Each stage has a voltage input (315, 315'"'"', 315") with an associated input capacitance and input threshold voltage, and a current output (316, 316'"'"', 316"). An active output circuit regulates the output currents so as to regulate the frequency of oscillation. A single reference circuit (307) can be used by more than one stage. The output circuit can vary the output currents to compensate for variable supply voltages. The oscillator can be used as part of a bias generator in an integrated circuit.
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Citations
18 Claims
- 1. A ring oscillator comprising, a plurality of cascaded inverting stages, each stage comprising an input circuit for detecting an output voltage of a preceding stage, characterized in that at least one inverting stage further comprises an output circuit having a current source that is controlled by said input circuit for supplying an output current to an input circuit of a succeeding stage.
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14. A ring oscillator comprising:
- an odd number plurality of inverting stages connected in cascade in a loop circuit, each stage comprising an input circuit and an output circuit with the input circuit coupled to the output circuit of a preceding inverting stage of the loop circuit and responsive to an output voltage at an output terminal of the output circuit, and a reference circuit coupled to the output circuit of at least one inverting stage, said reference circuit including a controlled transistor current source coupled to the input circuit of said one inverting stage and responsive to a voltage developed in said input circuit in a manner so as to control the output circuit to supply a controlled output current to the input circuit of a succeeding inverter stage of the loop circuit thereby to regulate the oscillation frequency of said ring oscillator.
- View Dependent Claims (15, 16, 17, 18)
Specification