Precision oscillators that use imprecise components
AssigneeTexas Instruments Incorporated
InventorsAniruddha Roy, Nitin Agarwal, Rajavelu Thinakaran
Life of this patent
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Abstract
Trimming components within an oscillator comprising: a trim-capable current source, wherein the trim-capable current source comprises a trimmable resistor and a trimmable current component, a comparator comprising a first input terminal that couples to the trim-capable current source and the second input terminal that couples to a reference voltage source, a switch coupled to the first input terminal and the trim-capable current source, and a trim-capable capacitor coupled to the switch, wherein the switch is coupled between the trim-capable capacitor and the trim-capable current source.
Claims18
A device comprising:
- a trim-capable current source that includes:
- a first resistor;
- a trim control configured to:
- measure a first portion current of a current;
- determine an offset based on the first portion current;
- and
- trim, based on the offset, the first resistor to generate an adjusted first portion current;
- and
- a trimmable current component configured to trim, based on a ratio, the adjusted first portion current to generate an adjusted current at an output of the trim-capable current source, wherein the ratio is based on a first voltage associated with the adjusted first portion current and a second voltage associated with a second portion current;
- a comparator comprising a first input terminal that couples to the output of the trim-capable current source and a second input terminal that couples to a reference voltage source;
- and
- a capacitor coupled to the first input terminal.
A method comprising:
- measuring a first portion current of a capacitor charging current from a trim-capable current source;
- determining an offset based on the first portion current;
- trimming, based on the offset, a resistor to generate an adjusted first portion current;
- and
- trimming, based on a ratio, the adjusted first portion current to generate an adjusted capacitor charging current, wherein the ratio is based on a first voltage associated with the adjusted first portion current and a second voltage associated with a second portion current.
An oscillator comprising:
- a first resistor;
- a second resistor;
- and
- a trim-capable current source configured to:
- measure a first portion current of a capacitor charging current generated from the trim-capable current source;
- determine a first offset based on the first portion current;
- and
- trim the resistance of the first resistor and the second resistor based on the first offset and trim a current component based on a first voltage associated with the first resistor and a second voltage associated with the second resistor.
Dependencies are inferred from the claim text.