Amplifier Offset Compensation with Settling-Phase Deactivation
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Solution Overview
Problem
Existing amplifier circuits with offset compensation arrangements face issues with overcompensation due to integrating behavior, leading to increased offset presence during frequent input signal level changes and settling operations, which corrupts measurement results.
Innovation Solution
A circuit arrangement with a deactivation circuit that temporarily deactivates the offset compensation arrangement during settling phases after input signal level changes, preventing incorrect detection of voltage differences as offsets and thereby avoiding overcompensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the offset compensation arrangement continuously detects and compensates for input voltage differences, then offset compensation is maintained during settled states, but erroneous compensation signals are generated during settling operations leading to overcompensation
Solution Approach 1:
The deactivation circuit temporarily disables the offset compensation arrangement before the operational amplifier completes its settling process. By anticipating the settling period and preventing compensation detection during this transient phase, the system avoids generating erroneous compensation signals while maintaining accurate compensation during settled states
2Stability of the object's composition
If the offset compensation arrangement operates continuously, then offset voltage is regulated to zero during settled states, but the compensation signal increases with each level change leading to overcompensation
Solution Approach 1:
The offset compensation arrangement operates in periodic cycles rather than continuously. The deactivation circuit introduces periodic interruptions that align with the operational amplifier's settling time constant, allowing the compensation system to reset and avoid cumulative overcompensation while maintaining stability during each settled phase
Data Source
AI summary
A circuit arrangement is disclosed herein comprising an amplifier circuit having inputs configured to receive an input signal, and an output configured to provide an output signal. The circuit arrangement further comprises a first operational amplifier. The first operational amplifier includes inputs coupled to the inputs of the amplifier circuit, an output coupled to the output of the amplifier circuit, and a first compensation input. The compensation input is configured to feed an offset compensation signal to the first operational amplifier. The circuit arrangement further comprises a first compensation circuit configured to provide the offset compensation signal. The first compensation circuit is coupled to the inputs of the first operational amplifier. The circuit arrangement further comprises a deactivation circuit which is designed to temporarily deactivate the first compensation circuit.