Dual-Capacitor Sampling Circuit for Cross-Domain Charge Retention
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Solution Overview
Problem
Existing sampling circuits face challenges in efficiently transferring high-voltage input signals to lower voltage domains without charge loss due to parasitic reverse diodes, especially when input signals vary quickly, leading to distortion and loss of charge during the conversion phase.
Innovation Solution
A circuit design that utilizes two capacitors operating in different voltage domains, where the first capacitor is charged during the sampling phase and the charge is transferred to a second capacitor during the holding phase, which is then processed in a separate conversion phase, decoupling the voltage domains and preventing charge loss through parasitic reverse diodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single capacitor is used to sample high-voltage input signals and transfer charge directly to the processing circuit, then the circuit structure is simple, but charge loss occurs due to parasitic reverse diodes when input signals vary quickly
Solution Approach 1:
The patent divides the charge transfer process into two separate capacitors: a first capacitor for sampling high-voltage input signals and a second capacitor for transferring charge to the processing circuit. This segmentation isolates the parasitic reverse diode effects to the first capacitor while the second capacitor maintains clean charge storage, resolving the contradiction between simple structure and reliable charge retention.
Solution Approach 2:
The first capacitor acts as an intermediary between the high-voltage input signal and the second capacitor. It absorbs the harmful effects of parasitic reverse diodes during rapid signal variations, allowing the second capacitor to receive charge without contamination, thus maintaining reliability while keeping the overall structure manageable.
2Adaptability or versatility
If transistors designed for high voltage are used to connect the input signal to the capacitor, then the circuit can handle high-voltage input signals, but parasitic reverse diodes cause charge to drain from the capacitor
Solution Approach 1:
The patent segments the voltage handling function from the charge storage function. The first capacitor and its associated high-voltage transistors handle the high-voltage input signal, while the second capacitor operates at lower voltage for clean charge storage. This segmentation allows high voltage adaptability while preventing charge loss in the storage capacitor.
Solution Approach 2:
The patent extracts the parasitic reverse diode problem from the charge storage path by placing it only in the first capacitor's circuit path. The second capacitor is isolated from high-voltage transistors and their parasitic diodes, eliminating charge loss while maintaining high-voltage handling capability through the first capacitor.
3Productivity
If the capacitor is isolated from the input signal in the conversion phase, then charge can be processed further, but charge may be lost through parasitic reverse diodes when input signals vary quickly
Solution Approach 1:
The patent segments the sampling and conversion phases into two separate capacitors. The first capacitor handles the sampling phase with high-voltage input signals, while the second capacitor handles the conversion phase with isolated charge storage. This ensures that charge information is preserved during isolation while still enabling signal processing.
Solution Approach 2:
The first capacitor serves as a mediator that captures charge during sampling and transfers it to the second capacitor during conversion. This intermediary role allows the second capacitor to be isolated from input signal variations and parasitic reverse diodes, preventing charge information loss while maintaining full signal processing capability.
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 solution effectively decouples voltage domains, preventing charge loss and distortion, allowing for accurate processing of high-voltage input signals in lower voltage domains, even when input signals fluctuate rapidly, by securing the charge on the second capacitor during the holding phase.
Implementation Method 1
a first capacitor (12), a second capacitor (13) and a processing circuit (14)
Implementation Method 2
to cause charge to be transferred from the first capacitor to the second capacitor in a second operating phase
Data Source
AI summary
A circuit having capacitors, and corresponding method. A circuit and corresponding methods are provided. A controller causes a first capacitor to be connected to an input connection in a first operating phase, charge to be transferred from the first capacitor to a second capacitor in a second operating phase and charge to be transferred from the second capacitor to a processing circuit in a third operating phase. The input connection and the second capacitor belong to different voltage domains.