Tunable Voltage Regulator Circuit for Stable Ripple Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing switched-current voltage regulators face challenges in maintaining stability over a wide load range and accommodating varying ripple voltage and load capacitor size requirements, making them difficult to adapt to different applications.

Innovation Solution

A hysteretic voltage regulator with an output driver current mirror circuit featuring a tunable resistance and control circuits, including comparators for feedback control, which sets the maximum frequency of output voltage and allows for smaller capacitors by adjusting resistance, thereby controlling di/dt slew rate and bandwidth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large capacitor is used at the output to ensure stability and minimize ripple, then stability and ripple control are improved, but the device complexity and component size increase

Engineering Contradiction:
ImprovestabilityVSAvoidcapacitor size
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the resistance value tunable/adjustable during operation. The resistance in the current mirror circuit can be dynamically changed to optimize performance for different operating conditions, allowing the use of smaller capacitors while maintaining stability across a wide load range.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the resistance parameter in the current mirror circuit to achieve different performance characteristics. By adjusting the resistance value, the circuit can maintain stability and control ripple with smaller capacitors, resolving the contradiction between capacitor size and stability.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the capacitor size is reduced to minimize component count, then device complexity decreases, but stability and ripple control deteriorate

Engineering Contradiction:
Improvecapacitor sizeVSAvoidstability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The tunable resistance allows the circuit to adapt dynamically, compensating for the reduced capacitor size. By adjusting the resistance value, the circuit maintains stability and ripple control performance even with smaller capacitors, enabling reduced device complexity without sacrificing reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the resistance parameter to optimize the circuit's transient response and stability characteristics. This parameter adjustment allows the use of smaller capacitors while maintaining the required stability and ripple performance.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If the regulator is designed for a specific application with fixed parameters, then manufacturing precision is improved, but adaptability to different applications deteriorates

Engineering Contradiction:
Improvedesign optimizationVSAvoidapplication range
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent implements a tunable resistance mechanism that allows the regulator to be adapted to different applications. The resistance can be adjusted to optimize performance for various load ranges, ripple requirements, and capacitor sizes, enabling a single design to serve multiple applications with different specifications.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The regulator circuit is designed with universal applicability through the tunable resistance parameter. This single circuit topology can be configured for different applications by adjusting the resistance value, making it versatile for various load ranges and capacitor sizes without requiring redesign.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Device complexity

If the resistance is reduced to allow smaller capacitors, then device complexity decreases, but di/dt control and bandwidth deteriorate

Engineering Contradiction:
Improvecapacitor sizeVSAvoiddi/dt control
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent uses a dynamically tunable resistance that can be adjusted to maintain optimal di/dt control and bandwidth even when using smaller capacitors. The resistance value can be changed based on operating conditions to preserve the desired current slew rate characteristics.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The resistance parameter is adjusted to achieve the desired balance between capacitor size and di/dt control. By changing the resistance value, the circuit maintains proper bandwidth and current slew rate characteristics while allowing the use of smaller capacitors.

Inventive Principle:
Principle #35Parameter changes

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 provides a stable voltage regulator that can be configured for various applications, using smaller capacitors while maintaining smooth di/dt slew rates and effective ripple control, enhancing adaptability and efficiency.

Implementation Method 1

a first comparator for controlling a first current to the output driver current mirror circuit in response to a first feedback signal from the output terminal

Methodology Applied
Scientific EffectFeedback control: Feedback

Implementation Method 2

The tunable resistance and the feedback signal together provide hysteresis for current switching

Methodology Applied
Scientific EffectHysteresis: Hysteresis

Data Source

PatentEP3273320B1Tunable voltage regulator circuit
Publication Date: 2019.09.18 NXP USA INC
  • EP3273320B1 patent drawingFigure 1
  • EP3273320B1 patent drawingFigure 2
  • EP3273320B1 patent drawingFigure 3

AI summary

A voltage regulator has an output driver current mirror circuit and one or more control circuits. The output driver current mirror circuit includes an output driver transistor, a tunable resistance circuit, and a diode-connected transistor. The output driver transistor has one current electrode coupled to a supply voltage and another current electrode coupled to an output terminal for providing the output voltage of the voltage regulator. The tunable resistance circuit has one terminal coupled to a control electrode of the output driver transistor, and another terminal coupled to a current electrode of the diode-connected transistor. The one or more control circuits includes a comparator for controlling a current provided to the output driver current mirror in response to a feedback signal from the output terminal.