Capacitive Signal Converter Switching to Prevent ADC Leakage Errors
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Solution Overview
Problem
Conventional ADCs face accuracy issues due to leakage currents caused by the location of additional switches across the capacitive network, which can lead to errors in signal conversion, especially when precharging for sampling.
Innovation Solution
A method involving a capacitive device that is first loaded to a preparation voltage in a first operating phase and then to a measuring voltage in a second phase, with an additional switch used to discharge the capacitive network before sampling to prevent leakage currents and ensure accurate conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an additional switch is placed directly across the capacitive network to discharge it before sampling, then the C-network can be completely discharged to enable error detection, but leakage currents occur that adversely influence conversion accuracy
Solution Approach 1:
The patent divides the discharge function into two separate switches: a first switch connected in parallel with the capacitive network for complete discharge (enabling error detection), and a second switch connected in series with the capacitive network to control leakage during sampling (maintaining conversion accuracy). This segmentation allows each switch to perform its specific function without causing the harmful effects that would occur if a single switch performed both functions.
2Productivity
If the C-network is precharged to minimize sample phase time, then sampling speed is improved, but leakage currents from the additional switch still affect accuracy
Solution Approach 1:
The patent segments the switch control functions by using a first switch for discharge operations and a second switch for sampling control. The second switch is specifically positioned to prevent leakage currents during the sampling phase while allowing the C-network to be precharged, thus maintaining both high sampling speed and high conversion accuracy without the harmful effects of leakage currents.
3Reliability
If the additional switch is used to discharge the C-network, then error detection is enabled, but the switch location causes leakage currents that reduce measurement precision
Solution Approach 1:
The patent implements segmentation by using two separate switches with distinct functions: the first switch (in parallel) enables complete discharge for error detection, while the second switch (in series) prevents leakage currents during measurement. This segmentation resolves the contradiction by ensuring that the discharge function and the measurement function are performed by separate components, eliminating the harmful interaction between them.
Solution Approach 2:
The second switch acts as an intermediary element between the capacitive network and the measurement circuit. By positioning the second switch in series with the capacitive network, it mediates the connection during sampling operations, preventing leakage currents from affecting the measurement while still allowing the first switch to perform discharge operations for error detection.
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 minimizes leakage currents and enhances the accuracy of signal conversion by isolating the capacitive network during the sampling phase, reducing errors associated with broken wires or bad soldering connections.
Implementation Method 1
loading a capacitive device to a preparation voltage in a first operating phase, and loading the capacitive device to a measuring voltage in a second operating phase
Data Source
AI summary
A system having a signal converter device, and a method for operating a system having a signal converter device is disclosed. One embodiment provides loading a capacitive device to a preparation voltage in a first operating phase, and loading the capacitive device to a measuring voltage in a second operating phase after the first operating phase.