Dual-Mode Voltage Regulator for Constant-Current Side-Channel Masking

Solution Overview

Problem

Existing voltage regulators struggle to operate in modes where the current drawn from the voltage source varies with the power consumption of the circuits, as well as modes where the current remains constant, which is necessary for masking power consumption and preventing side channel attacks.

Innovation Solution

A device comprising a MOS transistor, a selectively-activatable current source, and control circuits that allow the voltage regulator to switch between two operating modes: one where the current drawn varies with the power consumption, and another where the current remains constant, by adjusting the set point values and activating/deactivating components such as current sources and transistors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the voltage regulator operates in a mode where current drawn varies with power consumption, then power management efficiency is improved, but security against side channel attacks deteriorates

Engineering Contradiction:

Improvepower management efficiencyVSAvoidside channel attack vulnerability

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The voltage regulator dynamically switches between two operating modes based on security requirements. In the first mode, the current drawn from the voltage source varies with the power consumption of the circuits being powered, optimizing power management efficiency. In the second mode, the current drawn is maintained constant regardless of power consumption variations, providing security against side channel attacks. The system can transition between these modes as needed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes the electrical parameter (current) behavior by switching between two distinct operating modes. The first mode allows current to vary proportionally with power consumption, while the second mode maintains constant current. This parameter change is achieved through the voltage regulator's ability to adjust its operation based on control signals, enabling it to alter how current is drawn from the voltage source.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If the voltage regulator operates in a mode where current drawn is constant, then security against side channel attacks is improved, but power management efficiency deteriorates

Engineering Contradiction:

Improveside channel attack resistanceVSAvoidpower management efficiency

Core Design Contradiction:

Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The voltage regulator dynamically switches between two operating modes based on security requirements. In the first mode, the current drawn from the voltage source varies with the power consumption of the circuits being powered, optimizing power management efficiency. In the second mode, the current drawn is maintained constant regardless of power consumption variations, providing security against side channel attacks. The system can transition between these modes as needed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes the electrical parameter (current) behavior by switching between two distinct operating modes. The first mode allows current to vary proportionally with power consumption, while the second mode maintains constant current. This parameter change is achieved through the voltage regulator's ability to adjust its operation based on control signals, enabling it to alter how current is drawn from the voltage source.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If a single voltage regulator circuit is used, then device complexity is reduced, but operational versatility deteriorates

Engineering Contradiction:

Improvecircuit complexityVSAvoidoperating mode flexibility

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The voltage regulator is designed to perform multiple functions within a single circuit. It can operate in at least two distinct modes: a first mode where current drawn varies with power consumption for efficient power management, and a second mode where current drawn is constant for security applications. This multi-functionality is achieved through the voltage regulator's ability to switch between different operational states, allowing a single device to serve both power efficiency and security requirements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 the voltage regulator to efficiently adapt to different operational requirements, ensuring that the current drawn is either variable or constant as needed, thereby enhancing security and power management capabilities.

Implementation Method 1

a first MOS transistor connected between a first node configured to receive a first power supply voltage and a second node; a first circuit configured to control the first transistor to regulate a voltage of the second node to a first set point value at least partly determined by a first set point voltage

Methodology Applied

Scientific EffectMOS transistor conduction control:

Implementation Method 2

a second MOS transistor connected between the first node and a fourth node and having a gate connected to a gate of the first transistor; a third MOS transistor connected between the fourth node and a third node; a second circuit configured to control the third transistor to regulate a voltage of the fourth node to a second set point value at least partly determined by a second set point voltage

Methodology Applied

Scientific EffectMOS transistor conduction control:

Implementation Method 3

a switch connected between the second and fourth nodes

Methodology Applied

Scientific EffectElectrical switching:

Implementation Method 4

a selectively-activatable current source connected between the second node and a third node configured to receive a reference potential

Methodology Applied

Scientific EffectCurrent source operation:

Data Source

PatentUS20250076914A1Voltage regulator

Publication Date: 2025.03.06 STMICROELECTRONICS INT NV

AI summary

A device includes a first MOS transistor connected between first and second nodes, a selectively activatable current source connected between the second node and a third node and a circuit configured to control the first transistor to regulate a voltage at the second node to a first set point value. The device further includes a second MOS transistor connected between the first node and a fourth node, and having its gate connected to the gate of the first MOS transistor, a third MOS transistor connected between the third and fourth nodes, a switch connected between the second and fourth nodes, and another circuit configured to control the third transistor to regulate a voltage at the fourth node to a second set point value.