Dual-Input Linear Regulator for Multi-Voltage IC Cards

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Solution Overview

Problem

Integrated circuit cards face challenges in efficiently powering peripheral devices due to increased power demands and size constraints of voltage regulators, particularly when operating in both contact and contactless modes, and require a solution to provide a single integrated circuit capable of supplying various voltage levels for different external circuits.

Innovation Solution

A linear voltage regulator design that includes a first and second transistor between input and output terminals, an amplifier for voltage difference control, and switches controlled by digital signals, along with an antenna for capturing electromagnetic fields to provide power, allowing for dual interface operation and reduced regulator size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single integrated circuit is used to supply various voltage levels for different external circuits, then device complexity is reduced, but manufacturing precision requirements increase

Engineering Contradiction:
Improveregulator size and complexityVSAvoidvoltage regulation precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The regulator is divided into multiple independent modules: a first regulator for generating a first voltage level, a second regulator for generating a second voltage level, and a third regulator for generating a third voltage level. Each module operates independently to regulate its output voltage, ensuring precise voltage control while maintaining a compact integrated structure. This segmentation allows each regulator to be optimized for its specific voltage level without compromising overall system complexity.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the regulator supplies multiple voltage levels for contact and contactless modes, then adaptability increases, but device complexity increases

Engineering Contradiction:
Improvedual interface operation capabilityVSAvoidregulator structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The regulator is designed as a universal power supply system that can operate in both contact mode and contactless mode. The first regulator generates a first voltage level for contact mode operation, while the second and third regulators generate second and third voltage levels for contactless mode operation. This multi-functional design allows a single integrated circuit to serve multiple operating modes without requiring separate regulator circuits for each mode, thereby achieving adaptability while controlling complexity.

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

3Adaptability or versatility

If peripheral systems such as fingerprint sensors and displays are added to IC cards, then functionality increases, but power consumption increases

Engineering Contradiction:
Improveperipheral system functionalityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The regulator provides different voltage levels to different peripheral systems according to their specific power requirements. The first regulator supplies a first voltage level optimized for contact mode operation, while the second and third regulators supply second and third voltage levels optimized for contactless mode operation and peripheral devices such as fingerprint sensors and displays. This localized power optimization ensures that each peripheral system receives the appropriate voltage level, minimizing overall power consumption while maximizing functionality.

Inventive Principle:
Principle #3Local quality

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 enables efficient power supply to external systems with reduced regulator size and complexity, supporting multiple voltage levels and modes of operation, thereby enhancing mass-market production and versatility of integrated circuit cards.

Implementation Method 1

an antenna adapted to capture an electromagnetic field

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4235500B1IC card regulator
Publication Date: 2025.03.26 STMICROELECTRONICS RAZVOJ POLPREVODNIKOV D O O
  • EP4235500B1 patent drawingFigure 1~2
  • EP4235500B1 patent drawingFigure 3
  • EP4235500B1 patent drawingFigure 4~5

AI summary

The present disclosure relates to a linear voltage regulator (2) comprising: a first transistor (41) between a first input terminal (21), adapted to receive a first voltage (VCC), and an output terminal (28) adapted to provide a regulated voltage (VCC_OUT); a second transistor (45) between a second input terminal (26), adapted to receive a second voltage, and said output terminal; an amplifier of the difference between a third voltage proportional to the voltage at said output terminal, and a reference voltage (VREF), an output of said amplifier being selectively coupled to respective control terminals (44, 48) of said first and second transistors, said amplifier being supplied by a fourth voltage corresponding to the highest voltage between said first and second voltages.