Dual output amplifier for precision resistor calibration system
AssigneeQUALCOMM Incorproated
InventorsPrzemyslaw Jan Mroszczyk, Stephen Anthony Barry
Life of this patent
Estimating the term…
Abstract
An apparatus includes a multi-stage amplifier and a feedback switch. The multi-stage amplifier includes a first amplifier having a first input, a second input, and an output, a second amplifier having an input and an output, wherein the input of the second amplifier is coupled to the output of the first amplifier, and a third amplifier having an input and an output, wherein the input of the third amplifier is coupled to the output of the first amplifier. The feedback switch is coupled between the output of the third amplifier and the second input of the first amplifier.
Claims18
An apparatus, comprising:
- a multi-stage amplifier, wherein the multi-stage amplifier comprises:
- a first amplifier having a first input, a second input, and an output;
- a second amplifier having an input and an output, wherein the input of the second amplifier is coupled to the output of the first amplifier;
- and
- a third amplifier having an input and an output, wherein the input of the third amplifier is coupled to the output of the first amplifier;
- a feedback switch coupled between the output of the third amplifier and the second input of the first amplifier;
- and
- a control circuit coupled to the output of the second amplifier, wherein the control circuit is configured to adjust a resistance of a programmable resistor based on the output of the second amplifier.
An apparatus, comprising:
- a multi-stage amplifier, wherein the multi-stage amplifier comprises:
- a first amplifier having a first input, a second input, and an output;
- a second amplifier having an input and an output, wherein the input of the second amplifier is coupled to the output of the first amplifier;
- and
- a third amplifier having an input and an output, wherein the input of the third amplifier is coupled to the output of the first amplifier;
- a feedback switch coupled between the output of the third amplifier and the second input of the first amplifier;
- a first capacitor, wherein a terminal of the first capacitor is coupled to the first input of the first amplifier;
- a second capacitor;
- a first switch coupled between a first resistor and the first input of the first amplifier;
- a second switch coupled between a second resistor and a first terminal of the second capacitor, wherein a second terminal of the second capacitor is coupled to the second input of the first amplifier;
- and
- a third switch coupled between the first terminal of the second capacitor and the first input of the first amplifier.
A method of operating a multi-stage amplifier, the multi-stage amplifier including a first amplifier having a first input and a second input, a second amplifier, and a third amplifier, the method comprising:
- during a first phase,
- coupling an output of the third amplifier to the second input of the first amplifier;
- driving an input of the third amplifier using an output of the first amplifier;
- sampling a first voltage using a first capacitor;
- and
- coupling a second capacitor between the first input and the second input of the first amplifier;
- and
- during a second phase,
- driving an input of the second amplifier using the output of the first amplifier.
Dependencies are inferred from the claim text.