Leakage Current Supply Circuit for Lower LDO Headroom
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Solution Overview
Problem
Conventional low-dropout (LDO) voltage regulators face challenges in reducing headroom voltage, leading to increased power and energy consumption due to limitations in design, which restricts dynamic voltage and frequency scaling (DVFS) states, causing cores to operate at higher voltages even when lower voltages are feasible.
Innovation Solution
The introduction of a leakage current supply source with a sensor to determine leakage current demand and a supply circuit to provide current assistance, allowing the LDO voltage regulator to supply only dynamic current, thereby reducing headroom voltage and enabling more DVFS states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional LDO voltage regulator design is used, then the regulator can provide high bandwidth for fast current demand response, but the headroom voltage cannot be reduced sufficiently
Solution Approach 1:
The patent segments the current supply function by introducing a separate leakage current supply circuit that handles static leakage current, while the LDO regulator focuses on dynamic current. This segmentation allows the LDO to operate with lower headroom voltage since it only needs to handle dynamic variations, not the total current including leakage.
Solution Approach 2:
The leakage current supply circuit acts as an intermediary that provides the static leakage current component, allowing the LDO regulator to operate with reduced headroom. The sensor detects leakage current and the supply circuit delivers it separately, mediating between the power source and the LDO regulator.
2Productivity
If headroom voltage is reduced to enable more DVFS states, then energy optimization improves, but the LDO regulator cannot maintain sufficient current supply capability
Solution Approach 1:
The patent divides current supply into two segments: static leakage current handled by the dedicated supply circuit, and dynamic current handled by the LDO regulator. This allows the LDO to maintain adequate current capability for dynamic loads while operating at lower headroom voltage, enabling more DVFS states.
Solution Approach 2:
The leakage current supply circuit performs preliminary action by providing the static leakage current in advance, before the LDO regulator needs to handle dynamic current variations. This preliminary supply of leakage current allows the LDO to operate with reduced headroom while maintaining overall current supply capability.
3Reliability
If LDO regulator supplies all current including leakage, then complete current demand is met, but headroom voltage must be higher than desirable
Solution Approach 1:
The patent segments the total current demand into leakage current (handled by the dedicated supply circuit) and dynamic current (handled by the LDO regulator). This ensures complete current demand fulfillment while allowing the LDO to operate at lower headroom voltage since it only supplies the dynamic portion.
Solution Approach 2:
The leakage current supply circuit serves as an intermediary that handles the static leakage component, allowing the LDO regulator to focus on dynamic current supply. This intermediary arrangement ensures complete current fulfillment while reducing the headroom requirements of the LDO regulator.
Data Source
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AI summary
Systems and methods relate to a low-dropout voltage (LDO) voltage regulator which receives a maximum supply voltage and provides a regulated voltage to a load, where the load may be a processing core of a multi-core processing system. A leakage current supply source includes a leakage current sensor to determine a leakage current demand of the load of the LDO voltage regulator and a leakage current supply circuit to supply the leakage current demand. In this manner, the leakage current supply source provides current assistance to the LDO voltage regulator, such that the LDO voltage regulator can supply only dynamic current. Thus, headroom voltage of the LDO voltage regulator, which is a difference between the maximum supply voltage and the regulated voltage, can be reduced. Reducing the headroom voltage allows greater number of dynamic voltage and frequency scaling states of the load.