Regulator Circuit Dynamic Bias Current Control
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Solution Overview
Problem
Conventional regulator circuits experience significant output voltage drops when load current is large due to the constant output bias current flowing independent of the load current, leading to increased output voltage variation.
Innovation Solution
A regulator circuit is designed with a voltage detection circuit, error amplifier circuit, output circuit, current detection circuit, and current bias circuit that dynamically adjusts the output bias current based on load current detection to minimize voltage variations and prevent drops in output voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a constant output bias current is allowed to flow through NMOS transistor 204 to increase the minimum value of the output current, then the output voltage variation relative to the change in load current is suppressed, but when the load current is large, the output voltage drops significantly
Solution Approach 1:
The patent applies dynamics by transitioning from a static constant bias current to a dynamic variable bias current that adapts to load conditions. The bias current is adjusted based on the operational region detection of NMOS transistor 204, being supplied when operating in the linear region and reduced or stopped when operating in the saturation region, thereby optimizing output voltage stability across different load conditions while preventing excessive voltage drops at high currents
Solution Approach 2:
The patent implements feedback through detection circuits that monitor the operational region of NMOS transistor 204 and adjust the bias current accordingly. The first detection circuit detects saturation region operation and the second detection circuit detects linear region operation, providing feedback signals that control whether bias current is supplied, creating a closed-loop system that maintains optimal output voltage stability
2Reliability
If NMOS transistor 204 operates in a saturation region with constant bias current, then output voltage variation is reduced, but the circuit complexity increases due to multiple detection circuits and control mechanisms
Solution Approach 1:
The patent applies segmentation by dividing the control function into distinct detection circuits for different operational regions. The first detection circuit specifically detects saturation region operation while the second detection circuit detects linear region operation, allowing independent optimization of control strategies for each region without interfering with the other, thereby managing complexity through functional decomposition
Data Source
AI summary
A regulator circuit includes: a voltage detection circuit that detects a magnitude of an output voltage of an output node, and outputs a feedback voltage that indicates a result of the detection; an error amplifier circuit that compares the feedback voltage with a reference voltage, and outputs a voltage that indicates a result of the comparison; an output circuit that supplies an output current to the output node according to the voltage output by the error amplifier circuit; a current detection circuit that detects a magnitude of the output current; and a current bias circuit that supplies an output bias current to the output node, and increases or decreases the output bias current based on a result of the detection of the current detection circuit.