Voltage Regulator Impedance Compensation for Stable Load Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing voltage regulators face challenges in maintaining stable load voltages for varying load currents without the need for an extra feedback pin, which increases costs and complicates the design.
Innovation Solution
A voltage regulator with a pass transistor, feedback means, and compensation means that adjust the operation point based on sensed current and track impedance, allowing for stable output voltage without an extra feedback pin by using current sensing and impedance compensation to maintain load voltage stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional voltage regulator is used without impedance compensation, then the circuit is simpler and cost-efficient, but the load voltage becomes unstable when load current varies due to track voltage drops
Solution Approach 1:
The patent implements a feedback mechanism where the sensed current (proportional to load current) is fed back to the differential amplifier. This feedback loop allows the regulator to detect changes in load current and automatically adjust the pass transistor's gate voltage to compensate for track voltage drops, maintaining stable load voltage without requiring additional external feedback pins.
Solution Approach 2:
The patent introduces an intermediary current sensing mechanism that measures the load current indirectly through a sensed current proportional to the actual load current. This sensed current serves as a mediator between the load and the control circuit, enabling the regulator to respond to load changes without direct voltage feedback from the load terminal, thus avoiding the need for extra feedback pins while maintaining voltage stability.
2Reliability
If an extra feedback pin is added to sense load voltage directly, then load voltage stability improves, but manufacturing cost and device complexity increase
Solution Approach 1:
The regulator performs self-service by using its own internal current sensing capabilities to detect load current changes and automatically adjusting its output accordingly. The differential amplifier uses the sensed current to modulate the pass transistor, enabling the regulator to maintain stable load voltage without requiring external feedback components or additional pins, thereby reducing manufacturing complexity and cost.
Solution Approach 2:
The patent replaces the mechanical/physical connection of an extra feedback pin with an electrical signal substitution approach. Instead of directly sensing load voltage through an additional physical pin, the system substitutes this with an electrical signal derived from the sensed current that is proportional to load current, achieving the same control objective through electrical means rather than additional mechanical connections.
3Reliability
If the regulator adjusts output voltage to compensate for track voltage, then load voltage stability improves, but the regulator requires additional control mechanisms increasing complexity
Solution Approach 1:
The patent merges the current sensing function and voltage regulation control into a single integrated mechanism. The differential amplifier combines the reference voltage, feedback voltage, and sensed current signal to generate the gate voltage for the pass transistor. This merging of functions allows the regulator to compensate for track voltage drops using existing control circuitry without adding separate control mechanisms, thereby maintaining voltage stability while minimizing complexity.
Solution Approach 2:
The differential amplifier serves multiple functions: it compares the reference voltage with the feedback voltage, processes the sensed current signal, and generates the control voltage for the pass transistor. This multi-functionality allows the regulator to implement impedance compensation using the same control circuitry already present in the system, avoiding the need for additional dedicated control mechanisms and reducing overall device complexity.
Data Source
AI summary
A regulator configured to provide at an output node a load current at an output voltage is described. The regulator comprises a pass transistor for providing the load current at the output node. Furthermore, the regulator comprises feedback means for deriving a feedback voltage from the output voltage at the output node. In addition, the regulator comprises a differential amplifier configured to control the pass transistor in dependence of the feedback voltage and in dependence of a reference voltage. The regulator further comprises compensation means configured to determine a sensed current which is indicative of the load current at the output node. Furthermore, the compensation means are configured to adjust an operation point of the regulator in dependence of the sensed current and in dependence of a value of a track impedance of a conductive track which links the output node to a load.