Parallel Resistor Voltage Sensing With Differential Wiring Layout
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Solution Overview
Problem
Voltage detection devices for parallel resistance elements are prone to variations and errors due to the influence of pattern wiring configuration and temperature changes, leading to uneven current flow and impedance variations.
Innovation Solution
A voltage detection device with a configuration that connects one end and the other end of each resistance element in a resistance unit to a differential amplifier circuit through multiple wiring portions, minimizing the influence of wiring pattern configuration and temperature on the detected voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an operational amplifier is used to amplify a voltage signal in a high-impedance node, then the voltage signal can be detected, but the input capacitance of the operational amplifier causes the detected voltage to differ from the actual voltage
Solution Approach 1:
The patent extracts the capacitance effect from the operational amplifier by using a transmission gate to disconnect the operational amplifier's input capacitance from the high-impedance node during the measurement phase. This allows the voltage to be measured without the distorting effect of the operational amplifier's input capacitance, while still using the operational amplifier for signal amplification when needed.
Solution Approach 2:
The patent employs dynamic switching of the transmission gate to change the circuit configuration based on the measurement phase. During the measurement phase, the transmission gate connects the high-impedance node to the output node while disconnecting the operational amplifier. During the amplification phase, the transmission gate reconnects the operational amplifier. This dynamic switching resolves the contradiction by adapting the circuit configuration to the current operational requirement.
2Measurement precision
If the input capacitance of the operational amplifier is reduced, then voltage detection accuracy improves, but the amplification capability is degraded
Solution Approach 1:
The transmission gate dynamically switches between two operational modes: measurement mode where the high-impedance node is connected to the output node without the operational amplifier's input capacitance interference, and amplification mode where the operational amplifier is connected to amplify the voltage signal. This dynamic switching allows the system to achieve both high measurement precision and strong amplification capability at different times.
Solution Approach 2:
The measurement and amplification functions are segmented into separate operational phases controlled by the transmission gate. The measurement phase focuses exclusively on accurate voltage detection by isolating the high-impedance node from the operational amplifier's input capacitance, while the amplification phase focuses on signal boosting using the operational amplifier. This functional segmentation resolves the contradiction by allowing each function to operate optimally in its dedicated phase.
3Measurement precision
If a voltage detection device is provided in a data bus, then voltage signals can be monitored, but the input capacitance of the detection device causes voltage drops and affects normal data transmission
Solution Approach 1:
The transmission gate operates periodically, switching between measurement mode and transmission mode. During measurement mode, the high-impedance node is connected to the output node for voltage detection. During transmission mode, the transmission gate disconnects the detection path to allow normal data transmission without voltage drops. This periodic switching resolves the contradiction by allowing voltage monitoring and data transmission to occur at different time intervals without interfering with each other.
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
Reduces variations and errors in detected voltage by suppressing the impact of wiring pattern configuration and temperature, ensuring more accurate voltage measurements across varying conditions.
Implementation Method 1
when an operational amplifier 202 is used to amplify a voltage signal in a high-impedance node 201, an input capacitance of the operational amplifier 202 distorts an actual voltage of the high-impedance node 201
Data Source
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AI summary
To provide voltage detection device capable of reducing variations and errors in detection voltage caused by influence of configuration of pattern wiring and temperature when detecting voltages applied to a plurality of resistance elements connected in parallel. Voltage detection device includes resistance unit including a plurality of resistance elements connected in parallel, differential amplifier circuit, first connection portion having two wiring portions connecting positions different from each other in one end portion of resistance unit and input terminal of differential amplifier circuit, and second connection portion having two wiring portion connecting positions different from each other in other end portion of resistance unit and input terminal of differential amplifier circuit. Voltage detection device configures to detect voltage applied to resistance unit based on voltage of output terminal of differential amplifier circuit.