US 2019/0334509 A1 · SELF-COMPENSATED OSCILLATOR CIRCUIT

Abstract

A ring oscillator circuit is formed by series connected inverter circuits with a feedback loop. The inverter circuits are source biased with an oscillator voltage. A resistor-less bias current generator circuit generates a bias current for application to a replica inverter circuit to generate a bias voltage. A scaling circuit operates to scale the bias voltage by a selectable scaling factor to generate the oscillator voltage in a manner which balances a mobility effect of the inverter circuits within the ring oscillator circuit against a threshold voltage effect of the inverter circuits within the ring oscillator circuit. The clock signal output from the ring oscillator circuit has a frequency which is independent of process, voltage and temperature (PVT) spread.

Claims18

Dependent claims

A circuit, comprising:

a ring oscillator circuit comprising a plurality of inverter circuits connected in series with a feedback loop, said plurality of inverter circuits being source biased with an oscillator voltage;
a resistor-less bias current generator circuit configured to generate a bias current;
a replica inverter circuit that is source biased with the bias current to generate a bias voltage;
and
a scaling circuit configured to scale the bias voltage by a scaling factor to generate the oscillator voltage.

2 more elements

A circuit, comprising:

a ring oscillator circuit comprising a plurality of inverter circuits connected in series with a feedback loop, said plurality of inverter circuits being source biased with a bias current;
and
a resistor-less bias current generator circuit configured to generate the bias current.

Dependencies are inferred from the claim text.

Self-compensated oscillator circuit

Life of this patent

Self-compensated oscillator circuit

Life of this patent

Abstract

Claims18