Self-regulated reference for switched capacitor circuit
AssigneeMediatek Inc.
InventorWen-Hua Chang
Life of this patent
Estimating the term…
Abstract
A switched-capacitor circuit comprising a differential operational amplifier and a feedback circuit is described. In some embodiments, the feedback circuit may be configured to provide a reference voltage that is insensitive to temperature and/or process variations. In some embodiments, the feedback circuit may be configured to mitigate the time delay associated with one or more capacitors of the switched-capacitor circuit. The switched-capacitor circuit may be controlled by a pair of control signals. During a first phase, one or more capacitors may be charged, or discharged, through an input signal. During a second phase, the electric charge of the one or more capacitors may be retained.
Claims20
A switched-capacitor circuit, comprising:
- a differential operational amplifier;
- at least one capacitor coupled to an input of the differential operational amplifier;
- and
- a feedback circuit coupled to the input of the differential operational amplifier and an input of the switched-capacitor circuit, the feedback circuit being configured to receive a reference signal and to produce, based at least in part on the reference signal, at least one stabilized reference signal,
- wherein the feedback circuit comprises a flipped voltage follower and wherein the flipped voltage follower comprises an input connected to an output of a common source amplifier.
A switched-capacitor circuit, comprising:
- a differential operational amplifier;
- and
- at least one capacitor coupled to an input of the differential operational amplifier;
- and a feedback circuit coupled to the input of the differential operational amplifier and an input of the switched-capacitor circuit,
- wherein the feedback circuit exhibits a gain configured to cancel, at least in part, a capacitance of the at least one capacitor, and
- wherein the feedback circuit comprises a flipped voltage follower circuit and wherein the flipped voltage follower comprises an input connected to an output of a common source amplifier.
A switched-capacitor circuit, comprising:
- a differential operational amplifier;
- a first and a second capacitor, the first capacitor being coupled to an input of the differential operational amplifier;
- a first feedback circuit coupled to an output of the second capacitor, the input of the differential operational amplifier, and an input of the switched-capacitor circuit, the first feedback circuit being configured to receive a reference signal and to produce, based at least in part on the reference signal, at least one stabilized reference signal;
- and
- a second feedback circuit coupled to an output of the first capacitor and an input of the second capacitor.
A switched-capacitor circuit, comprising:
- a differential operational amplifier;
- a first and a second capacitor, the first capacitor being coupled to an input of the differential operational amplifier;
- a first feedback circuit coupled to an output of the second capacitor, the input of the differential operational amplifier and an input of the switched-capacitor circuit;
- and
- a second feedback circuit coupled to an output of the first capacitor and an input of the second capacitor,
- wherein the first feedback circuit exhibits a gain configured to cancel, at least in part, a capacitance of the first capacitor.
Dependencies are inferred from the claim text.