Stabilizing reference voltage of switched capacitor circuits

摘要

A system includes a switched capacitor circuit and a stabilizing circuit. The switched capacitor circuit receives a reference voltage from a reference node, transitions from a first state to a second state, and draws or supplies a switched capacitor charge from or to the reference node in response to transitioning from the first state to the second state. The second state is a function of the first state, an input of the switched capacitor circuit, or a combination of both. The stabilizing circuit stabilizes the reference voltage by supplying or drawing a stabilizing charge to or from the reference node based on the first and second states of the switched capacitor circuit.

主权项

1. A system comprising:
a switched capacitor circuit that has a first state, wherein the first state is a function of an input of the switched capacitor circuit; that receives a reference voltage from a reference node; that transitions from the first state to a second state in response to a change in the input of the switched capacitor circuit, wherein the second state is a function of the first state or the input of the switched capacitor circuit; and that draws or supplies a switched capacitor charge from or to the reference node in response to transitioning from the first state to the second state; a stabilizing circuit that stabilizes the reference voltage by supplying or drawing a stabilizing charge to or from the reference node based on the first and second states of the switched capacitor circuit; a feedback circuit that is connected to the reference node and that generates a feedback of the reference voltage; and a buffer that receives the feedback and a first voltage and that supplies a buffer charge to the reference node, wherein the buffer charge compensates for a positive or negative error in estimation of the stabilizing charge.