Temperature-Adaptive LDO Correction Circuit for Stable Supply Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional low dropout regulators (LDOs) face instability issues due to increased load current with temperature, leading to malfunctions like oscillation and excessive current draw, and existing solutions either violate maximum supply current specifications or increase IC size and complexity.
Innovation Solution
A correction circuit dynamically adjusts the supply current to the LDO based on measured temperature using a thermometer code to selectively enable or disable parallel current paths, ensuring stability without exceeding maximum current specifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the LDO is designed to accommodate the maximum supply current specification to ensure stability at high temperatures, then stability is improved, but the typical supply current specification is violated
Solution Approach 1:
The patent implements dynamic adjustment of the LDO supply current based on temperature conditions. A correction circuit receives temperature data and dynamically modifies the supply current to the LDO, increasing it when temperature exceeds a threshold to maintain stability, and reducing it when temperature is normal to meet typical current specifications. This dynamic approach resolves the contradiction by adapting the current level to actual operational needs rather than using a fixed conservative design.
Solution Approach 2:
The patent changes the supply current parameter based on temperature conditions. The correction circuit adjusts the current magnitude dynamically, transitioning between different current levels depending on whether the temperature exceeds the threshold. This parameter change allows the system to meet stability requirements at high temperatures while maintaining compliance with typical current specifications under normal operating conditions.
2Reliability
If conventional approaches place large capacitors to improve LDO stability, then stability is improved, but IC size and design complexity increase
Solution Approach 1:
The patent extracts the stability correction function from the main LDO design and implements it as a separate correction circuit. This correction circuit independently adjusts the supply current based on temperature, removing the need for large capacitors and complex compensation networks that would otherwise be required to ensure stability across all temperature conditions. The extraction of this specific function reduces overall IC complexity while maintaining stability.
3Reliability
If additional current draw is added to handle load current variations, then LDO stability is improved, but maximum supply current specification is violated
Solution Approach 1:
The patent dynamically changes the supply current parameter based on temperature conditions rather than using a fixed higher current level. The correction circuit monitors temperature and adjusts the current magnitude accordingly, ensuring additional current is only drawn when necessary (when temperature exceeds threshold and stability is at risk), rather than continuously drawing excess current to cover all possible scenarios.
Solution Approach 2:
The patent implements a feedback mechanism where the correction circuit receives temperature data and uses this information to adjust the supply current to the LDO. This closed-loop approach ensures that current adjustments are made only when and where needed based on actual temperature conditions, preventing unnecessary current draw while maintaining stability when required.
Data Source
AI summary
Technologies related to low dropout regulation circuitry stabilization are described. A circuit includes an amplifier to supply a voltage based on a comparison of a feedback loop voltage and a reference voltage. A comparison circuit coupled to the amplifier dynamically adjusts an amount of current supplied to the amplifier based on a measured temperature.