LDO Voltage Regulation With Feedback Headroom Compensation
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Solution Overview
Problem
Conventional voltage regulating circuits in mobile devices face challenges in maintaining an adequate operating voltage due to path impedances, leading to voltage drops that cause logic abnormalities in digital logic circuits, especially as power consumption increases and battery capacities are not fully utilized.
Innovation Solution
A voltage regulating circuit comprising a low-dropout regulator and a reference voltage generating circuit that compensates for voltage differences between feedback terminals, using switches and current mirrors to detect and adjust for IR drops in power and ground path impedances, ensuring a stable voltage margin for the loading circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If path impedances are reduced to minimize voltage drop, then voltage stability is improved, but device complexity increases due to additional compensation circuits
Solution Approach 1:
The patent implements feedback mechanisms by detecting the actual voltage at the load terminals through feedback terminals and comparing it with the intended voltage, then adjusting the regulator output to compensate for IR drops. This closed-loop feedback system maintains voltage stability without requiring physical reduction of path impedances.
Solution Approach 2:
The patent introduces intermediary feedback terminals and voltage detection circuits that act as mediators between the regulator and the load. These intermediaries measure the actual voltage conditions and transmit this information back to the regulator, enabling indirect control of voltage stability without directly modifying the power delivery path.
2Device complexity
If voltage regulation is simplified to reduce device complexity, then manufacturing is easier, but voltage headroom is insufficient causing logic abnormalities
Solution Approach 1:
The patent applies preliminary action by pre-compensating for expected IR drops through feedback mechanisms. Before logic operations occur, the system detects voltage sags and adjusts the regulator output in advance to maintain adequate voltage headroom, preventing logic abnormalities before they occur.
Solution Approach 2:
The patent dynamically changes the regulator output voltage parameter based on detected load conditions and path impedance effects. By adjusting the output voltage parameter in response to feedback signals, the system maintains sufficient voltage headroom for reliable logic operation without requiring overly complex fixed compensation circuits.
3Device complexity
If path impedances are increased to simplify power delivery, then device complexity decreases, but voltage operation range is narrowed causing logic abnormalities
Solution Approach 1:
The patent introduces dynamics into the power delivery system by making the regulator output adjustable and adaptive based on real-time feedback. Instead of a fixed simple power delivery path, the system dynamically modifies its output characteristics to compensate for impedance effects, maintaining adequate voltage operation range across varying load conditions.
Solution Approach 2:
The feedback mechanism allows the system to detect when voltage sags occur due to path impedances and automatically adjust the regulator output to compensate. This feedback loop preserves the voltage operation range needed for logic operations even when using simpler power delivery paths with higher impedances.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively maintains a stable voltage difference between feedback terminals, preventing logic abnormalities and ensuring the digital logic circuit operates with enough margin under both light and heavy loading conditions, even with significant path impedances present.
Implementation Method 1
a voltage difference between two terminals of the digital logic circuit DLC is affected because of an IR drop of the power path impedance RAPR_PWR and the ground path impedance RAPR_GND
Data Source
AI summary
A voltage regulating circuit includes a low-dropout regulator, configured to provide a driving voltage to drive a loading circuit and receive a first detection voltage from a first feedback terminal; and a reference voltage generating circuit, coupled to the low-dropout regulator, configured to receive a second detection voltage from a second feedback terminal. A voltage difference between the first feedback terminal and the second feedback terminal is clamped according to the first detection voltage and the second detection voltage.