Voltage Integrating Circuit Offset Compensation via Replica Current
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Solution Overview
Problem
Conventional voltage integrating circuits with low gain or slow response speed operation amplifiers suffer from variable offset voltages, leading to reduced performance and accuracy in output voltage generation.
Innovation Solution
Incorporating a current source that draws a replica current from the capacitor, maintaining a constant voltage on the negative input end of the operation amplifier, thereby stabilizing the offset voltage and ensuring high accuracy output voltage generation even with low gain or slow response speed operation amplifiers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a low gain or slow response speed operation amplifier is used, then device complexity is reduced, but measurement precision deteriorates due to variable offset voltage
Solution Approach 1:
The patent uses a current mirror circuit to create a replica of the input current IIN. This copied current is then used to generate a compensating voltage that counteracts the offset voltage variations. By copying the current waveform and using it for compensation, the system maintains measurement precision without requiring high-performance operation amplifiers.
Solution Approach 2:
The patent implements a feedback mechanism where the output voltage Vout is continuously monitored and fed back through the capacitor C1 to the negative input end of the operation amplifier. This feedback loop, combined with the compensation voltage Vcomp, automatically adjusts to counteract offset voltage variations, maintaining output accuracy even with low gain or slow response speed amplifiers.
2Use of energy by moving object
If the operation amplifier has slow response speed, then power consumption is reduced, but reliability deteriorates due to variable offset voltage affecting output accuracy
Solution Approach 1:
The feedback mechanism continuously monitors the output voltage and adjusts the compensation voltage in real-time to counteract offset variations. This ensures reliable and stable output voltage even when using low-power operation amplifiers with slower response speeds.
Solution Approach 2:
The compensation voltage Vcomp is generated in advance based on the copied current waveform before the offset voltage variations fully manifest. This preliminary compensation action prevents accuracy degradation rather than correcting it after the fact, maintaining reliability with low-power amplifiers.
Data Source
AI summary
The invention provides a temperature detecting apparatus, a switch capacitor apparatus and a voltage integrating circuit. The voltage integrating circuit includes an operating amplifier, a capacitor and a current source. The operating amplifier has a positive input end, a negative input end and an output end. The output end of the operating amplifier generates an output voltage, and the positive input end receives a reference voltage. The capacitor is coupled between the output end and the negative input end of the operating amplifier. The current source is coupled to the output end of the operating amplifier. The current source draws a replica current from the capacitor, and a current level of the replica current is determined according to a current level of a current flowing to the negative input end of the operating amplifier.