Linear Voltage Regulator With Bitstream DAC Control

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Solution Overview

Problem

Existing linear voltage regulators face design complexity and inefficiencies due to the interdependence of converter and digital to analog converter circuits, which limits flexibility and increases power consumption and circuit area.

Innovation Solution

A linear voltage regulator design that includes a converter circuit producing a serial bitstream indicative of the voltage difference between the regulated and reference voltages, allowing for separate optimization of converter and digital to analog converter circuits, with an averager circuit controlling the power transistor's voltage based on pulse density, and utilizing a level shifting buffer to simplify the design and reduce power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If converter and digital to analog converter circuits are designed as interdependent units, then voltage regulation accuracy is maintained, but design flexibility is limited and circuit complexity increases

Engineering Contradiction:
Improvedesign flexibilityVSAvoidcircuit complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent divides the voltage regulator into separate functional modules: a converter circuit that generates a control signal based on voltage error, and a digital-to-analog converter circuit that independently processes this signal. This segmentation allows each module to be optimized separately, improving design flexibility while maintaining overall regulation accuracy through their coordinated interaction.

Inventive Principle:
Principle #1Segmentation

2Use of energy by stationary object

If traditional interdependent converter and DAC circuits are used, then voltage regulation function is achieved, but power consumption increases and circuit area expands

Engineering Contradiction:
Improvepower consumptionVSAvoidvoltage regulation accuracy
Core Design Contradiction:
Use of energy by stationary objectVSReliability

Solution Approach 1:

The patent replaces traditional analog feedback mechanisms with a digital-based control approach. The converter circuit generates a digital control signal representing voltage error, which is then converted to analog form only at the final actuation stage. This substitution reduces continuous analog signal processing, lowering power consumption while maintaining regulation accuracy through precise digital control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If separate optimization of converter and digital to analog converter circuits is implemented, then design flexibility and power efficiency improve, but circuit design complexity increases

Engineering Contradiction:
Improvedesign efficiencyVSAvoiddesign complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent creates a universal control interface between the converter and DAC circuits through standardized signal protocols. The converter circuit outputs a control signal in a standardized format that the DAC circuit can universally process, allowing separate optimization of each module while simplifying their integration. This universal interface reduces the complexity burden of separate design by providing a common communication framework.

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

Data Source

PatentEP4227756A1Linear voltage regulator
Publication Date: 2023.08.16 NXP BV
  • EP4227756A1 patent drawingFigure 1
  • EP4227756A1 patent drawingFigure 2
  • EP4227756A1 patent drawingFigure 3

AI summary

A linear voltage regulator includes a converter circuit that provides a serial bitstream having a pulse density that is indicative of a difference between a regulated voltage of the linear voltage regulator and a reference voltage. The linear voltage regulator also includes a digital to analog converter circuit that includes an input to receive the serial bitstream. The digital to analog converter circuit includes an averager circuit that produces an output signal to control a voltage of a control terminal of a power transistor of the linear volage regulator for regulating the regulated voltage based on the pulse density of the serial bitstream.