Cyclically Swapped Standby Capacitors for Rapid Voltage Assertion
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Solution Overview
Problem
Existing electronic circuits face limitations in rapidly and precisely changing the DC voltage across capacitors due to non-ideal capacitor behavior, slow settling times, and high-frequency instability, which affects applications requiring high dynamic range and accurate signal processing.
Innovation Solution
The implementation of a sub-circuit using cyclically swapped capacitors, where one capacitor is active and another is on standby, allowing controlled interchange of plates via electronic switches to achieve rapid voltage changes, replacing settling time with switch transition time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a capacitor is used to store voltage with high precision, then measurement precision is improved, but settling time increases to hundreds of microseconds or milliseconds
Solution Approach 1:
The capacitor is divided into two separate capacitors that can be independently controlled. One capacitor can be charged to the desired voltage while the other is discharged, allowing parallel processing of charge transfer operations and eliminating the sequential settling time limitation.
Solution Approach 2:
A third capacitor is introduced as an intermediary element to facilitate charge transfer between the two main capacitors. This intermediary capacitor enables controlled voltage assertion without requiring the main capacitor to settle through its inherent RC time constant.
2Speed
If the resistance in the RC network is reduced to decrease settling time, then speed is improved, but oscillations are induced in the feedback loop
Solution Approach 1:
The feedback loop is segmented into multiple independent paths, each with its own capacitor. This allows the resistance to be reduced for faster charging without compromising the stability of the overall system, as each segment can be independently optimized.
Solution Approach 2:
A second capacitor is introduced as a copy of the first, allowing the system to achieve the desired voltage assertion speed without modifying the original RC network parameters. The copy capacitor can be charged rapidly while the original maintains stability.
3Ease of operation
If op amps with non-zero output impedance are used to assert voltage on capacitor, then ease of operation is improved, but settling time increases due to RC time constant
Solution Approach 1:
The voltage assertion is performed in advance by charging a standby capacitor to the desired voltage level before it is needed. When voltage assertion is required, the pre-charged capacitor is rapidly connected to the target node, eliminating the need for slow charging through the op amp's output impedance.
Solution Approach 2:
A third capacitor serves as an intermediary that has been pre-charged to the desired voltage. This intermediary capacitor transfers charge rapidly to the target capacitor through low-impedance switches, bypassing the op amp's output impedance limitation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces settling times from hundreds of microseconds to hundreds of nanoseconds, enhancing the speed and precision of voltage changes across capacitors in various electronic circuits.
Implementation Method 1
A capacitor is a passive electrical component used to store energy in an electric field, typically comprising a pair of conductors separated by an insulator or dielectric. When there is a potential difference or voltage, across the conductors, a static electric field develops across the dialectic, causing positive charge to collect on one plate and negative charge on the other plate.
Implementation Method 2
When there is a potential difference or voltage, across the conductors, a static electric field develops across the dialectic, causing positive charge to collect on one plate and negative charge on the other plate. Energy is stored in the electrostatic field.
Implementation Method 3
The electronic switches allow the controlled interchange of one or both plates of the standby capacitors and/or the active capacitors when an electronic signal is activated
Data Source
AI summary
A circuit that can rapidly and precisely change the state of any circuit with some form of memory, whether it is a voltage across a capacitor, a current in an inductor, a digital value, or otherwise, using cyclically swapped circuits. For the case of a value stored on a capacitor: By swapping extra capacitors with preemptively set voltages using electronic switches, inherent settling times and defects of real RC circuits can be replaced with electronic switching times and switch defects. This dramatically improves speed and performance and is applicable on many circuit types including faster acquisition sample and hold circuits, faster amplifier nulling circuits, and any circuit that requires rapidly changing the DC voltage stored on a capacitor, and any circuit that requires rapidly changing the state or a circuit that has memory.