Ladder-Based Switch Regulator Without Miller Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional voltage regulators, such as low-dropout (LDO) regulators, face challenges in balancing stability and speed while maintaining a stable power supply, particularly in highly portable, low-power devices, due to limitations in bandwidth and response time caused by compensation circuits and decoupling capacitance.
Innovation Solution
A ladder-based high-speed switch regulator is introduced, which employs multiple comparators and pass elements to regulate voltage without a compensation circuit, enabling faster response times and increased bandwidth by dynamically adjusting current drivability based on reference voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If compensation circuits and decoupling capacitance are used in conventional voltage regulators, then stability is improved, but response time increases and bandwidth decreases
Solution Approach 1:
The patent removes the compensation circuit from the voltage regulator architecture. By extracting this stabilizing component, the invention achieves faster response times and higher bandwidth while maintaining stability through an alternative control mechanism using a comparator that directly compares output voltage with a reference voltage and adjusts the pass element accordingly.
Solution Approach 2:
The patent replaces the traditional feedback-based stability mechanism (compensation circuits) with a direct comparison and control mechanism. The comparator directly compares voltages and controls the pass element without requiring compensation circuits or large decoupling capacitance, substituting the mechanical/electrical feedback loop with a more direct voltage comparison approach.
2Stability of the object's composition
If decoupling capacitance is increased to maintain stability, then stability is improved, but chip layout area increases
Solution Approach 1:
The patent eliminates the requirement for large decoupling capacitance by removing the compensation circuit. This extraction of the stabilizing function to a different mechanism (direct voltage comparison) allows for significant reduction in chip layout area while maintaining stability.
Solution Approach 2:
The patent changes the stability maintenance approach from using large capacitance values to using an active voltage comparison and control mechanism. This parameter change from passive energy storage (capacitance) to active control (comparator and pass element modulation) reduces the physical area required on the chip.
3Speed
If bandwidth is increased to improve response speed, then response time is improved, but stability deteriorates
Solution Approach 1:
The patent implements a direct feedback mechanism where the comparator continuously compares the output voltage with the reference voltage and immediately adjusts the pass element to correct any deviation. This direct feedback loop provides both high bandwidth for fast response and inherent stability through the negative feedback control action.
Solution Approach 2:
The patent uses a dynamic control approach where the pass element is continuously adjusted based on the real-time comparison between output and reference voltages. This dynamic modulation allows the system to respond quickly to changes while maintaining stability through continuous correction, avoiding the trade-off between speed and stability.
Data Source
AI summary
Some embodiments include apparatuses having a switch regulator that includes a first circuit with a first comparator to compare an output of the switch regulator to a first reference voltage, and to provide a control signal to enable or disable a first pass element based on the comparison. The switch regulator includes at least a second circuit having a second comparator to compare an output of the switch regulator to a second reference voltage that is lower than the first reference voltage, and to provide a control signal to enable or disable a second pass element based on the comparison. The switch regulator does not include Miller compensation circuits. Other apparatuses and methods according to other embodiments are described.