Push-Pull Amplifier Bias Control for Low-Idle Distortion
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Solution Overview
Problem
Existing amplification devices face challenges in maintaining low energy consumption during idle states while preserving distortion characteristics, and they often rely on specific operational amplifier configurations that limit their effectiveness.
Innovation Solution
The proposed amplification device incorporates a push-pull circuit, a diamond buffer circuit, and current mirror circuits connected to the power supply and retraction current terminals, which allow for adaptive bias current adjustment based on input signal levels, ensuring sufficient current flow for distortion prevention and minimizing energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If constant current circuits are added to suppress bias current decrease, then bias current stability is improved, but device complexity increases and energy loss increases due to requiring sufficient current flow in advance
Solution Approach 1:
The patent combines the bias current supply function with the signal amplification function by using the same current path. The operational amplifier's power supply current is utilized to provide bias current to the diamond buffer circuit through the emitter resistor, eliminating the need for separate constant current circuits while maintaining bias stability.
Solution Approach 2:
The operational amplifier's power supply terminal serves multiple functions: it provides power to the operational amplifier itself and simultaneously serves as a current source for the diamond buffer circuit's bias current. This multi-functional use reduces overall circuit complexity and component count.
2Reliability
If sufficient bias current is supplied in advance to prevent distortion, then distortion characteristics are improved, but energy consumption increases during idle states
Solution Approach 1:
The patent implements dynamic bias current adjustment where the bias current supplied to the diamond buffer circuit varies according to the signal level. During large signal operation, sufficient bias current is automatically provided to prevent distortion, while during idle or small signal states, the bias current is reduced to minimize energy consumption. This is achieved through the operational amplifier's power supply current dynamically tracking the signal amplitude.
3Quantity of substance
If separate constant current circuits are used to maintain bias current, then bias current sufficiency is improved, but current flexibility decreases as current is fixed in advance
Solution Approach 1:
The patent employs feedback mechanisms where the operational amplifier monitors the signal level and automatically adjusts the bias current supplied to the diamond buffer circuit. The power supply current of the operational amplifier serves as a feedback-controlled current source that adapts to signal conditions, providing sufficient current when needed while maintaining flexibility to reduce current during low-demand periods.
Data Source
AI summary
An amplification device comprising: a push pull circuit which amplifies an input signal; a diamond buffer circuit to which the signal which is amplified by the push pull circuit is input; and a current mirror circuit which is connected to a power supply and the diamond buffer circuit and is connected to a retraction current terminal of the push pull circuit.