Sample-and-Hold Recovery Circuit for Voltage Droop Compensation
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Solution Overview
Problem
Conventional sample and hold circuits experience significant droop in output voltage due to capacitor discharge during the holding stage, leading to inaccuracies in signal conversion and measurement.
Innovation Solution
A recovery circuit comprising a buffer and filter module, an AC inverter and extractor module, and a summing amplifier that combine signals to produce an output with nearly constant voltage by compensating for droops through inverted AC component signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If conventional sample and hold circuits use capacitor discharge during the holding stage, then the circuit can hold the sampled voltage, but significant voltage droop occurs leading to measurement inaccuracies
Solution Approach 1:
The recovery circuit applies preliminary anti-action by generating an inverted AC component signal that anticipates and counteracts the droop effect before it degrades the measurement. The circuit extracts the AC component, inverts its phase, and adds it back to the conditioned signal, creating a compensating voltage that offsets the capacitor discharge droop during the holding stage.
Solution Approach 2:
The recovery circuit converts the harmful droop effect into a beneficial compensation mechanism. By extracting the AC component of the sampled signal, inverting its phase, and recombining it with the conditioned signal, the circuit generates a compensating voltage that benefits from the original signal characteristics while counteracting the harmful droop, thereby improving voltage accuracy during the holding period.
2Stability of the object's composition
If larger capacitors are used to reduce droop, then voltage stability improves, but device complexity and cost increase
Solution Approach 1:
The recovery circuit applies parameter changes by transforming the voltage signal through conditioning, AC extraction, and phase inversion operations. Instead of changing the physical capacitor size, the circuit changes the electrical parameters of the signal by adding an inverted AC component that compensates for droop, achieving voltage stability through signal processing rather than hardware scaling.
Solution Approach 2:
The recovery circuit introduces intermediary processing stages between the sample and hold circuit and the output. The buffer and filter module, AC component extractor, and summing amplifier act as intermediaries that process the sampled signal and add compensating components, mediating between the imperfect held voltage and the required stable output without needing larger capacitors.
3Volume of moving object
If smaller capacitors are used to reduce device size, then device compactness improves, but voltage droop increases reducing measurement accuracy
Solution Approach 1:
The recovery circuit creates a copy of the AC component of the sampled signal, inverts its phase, and adds it to the conditioned signal. This copying approach allows the use of smaller capacitors because the compensating inverted AC component replicates and counteracts the droop effect that would otherwise require larger capacitor values to suppress.
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
The recovery circuit significantly reduces voltage variation to less than 0.002% over time, enhancing the accuracy and performance of sample and hold circuits without requiring larger capacitors or lower input impedance.
Implementation Method 1
a buffer and filter module that conditions the sampled signal by filtering out high-frequency noise and amplifying the signal
Implementation Method 2
an AC component extractor that removes the DC component from the conditioned signal using capacitive coupling
Implementation Method 3
an inverting amplifier that inverts the phase of the AC component signal by 180 degrees
Implementation Method 4
a summing amplifier that combines the conditioned signal and the inverted AC component signal to produce an output signal with reduced droop
Data Source
AI summary
A recovery circuit includes a buffer and filter module that receives a sampled signal with droops between spikes over an interval of time from a sample and hold circuit and outputs a conditioned signal that has droops. The recovery circuit includes an alternating current (AC) inverter and extractor module that removes a direct current (DC) component of the conditioned signal and provides an inverted AC component signal that has signal boosts with an equal magnitude and duration to the droops in the conditioned signal. The recovery circuit also includes a summing amplifier that combines the conditioned signal and the inverted AC component signal to provide a output signal that has a nearly constant voltage over the interval of time.