MEMS Sensor Power-Down Architecture for Leakage Current Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

MEMS sensor devices face high power consumption in inactive states due to leakage currents, which is a challenge in low-power applications like wearable devices, and existing multi-domain approaches increase circuit complexity and power consumption.

Innovation Solution

Implementing a microelectromechanical sensor device with distinct voltage domains, including an always-on core and a selectively powerable second domain, where the voltage regulator is powered off in deep power-down conditions to minimize consumption, and a soft power-down condition where circuit stages are switched off to reduce power usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a multi-domain approach is used to reduce power consumption by selectively powering domains, then power consumption in inactive state is reduced, but circuit complexity and control burden increase

Engineering Contradiction:
Improvepower consumption in inactive stateVSAvoidcircuit complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent merges the power management functionality into a single unified domain architecture. Instead of implementing separate power supply switches for each domain, the invention combines all domains under one power supply that can be selectively activated or deactivated as a group, thereby reducing circuit complexity while maintaining power consumption benefits.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements a universal power supply structure that serves multiple functions: it powers all domains simultaneously, enables selective domain activation/deactivation through a single control mechanism, and provides both deep power-down and soft power-down modes. This multi-functional approach eliminates the need for multiple dedicated power supply switches.

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

2Use of energy by moving object

If power supply switches are implemented externally to control domains, then selective domain activation is achieved, but size occupation and control burden increase

Engineering Contradiction:
Improvepower consumptionVSAvoidsize occupation
Core Design Contradiction:
Use of energy by moving objectVSArea of stationary object

Solution Approach 1:

The patent integrates the power supply control functionality directly into the sensor device architecture rather than using external switches. By merging the power supply and control logic into a unified internal structure, the invention reduces external component requirements and minimizes size occupation while maintaining selective domain activation capability.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If control logic is implemented in the digital part to manage power supply switches, then domain switching is controlled, but power consumption increases in power-down condition

Engineering Contradiction:
Improvedomain switching controlVSAvoidpower consumption in power-down condition
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent extracts the essential power management functionality from the complex digital control logic and implements it through a simplified control mechanism. By separating the critical power supply control functions from the full digital processing logic, the invention enables effective power-down mode operation with minimal power consumption while retaining domain switching capability.

Inventive Principle:
Principle #2Taking out (Extraction)

4Use of energy by moving object

If voltage regulators are used to provide under-regulated voltage to digital part, then power consumption is reduced, but leakage current management becomes challenging

Engineering Contradiction:
Improvepower consumptionVSAvoidleakage current management
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent dynamically changes the voltage supply parameters based on operational state. By adjusting the voltage level provided to different domains according to whether they are active or in power-down mode, and by implementing both deep and soft power-down voltage levels, the invention effectively manages leakage currents while maintaining optimal power consumption characteristics.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4390623A9Microelectromechanical sensor device with improved management of a power-down condition
Publication Date: 2024.09.04 STMICROELECTRONICS INT NV
  • EP4390623A9 patent drawingFigure 1
  • EP4390623A9 patent drawingFigure 2~9
  • EP4390623A9 patent drawingFigure 3

AI summary

A microelectromechanical sensor device (1) has a detection structure (66) and an associated electronic circuitry (2), configured to receive, when the device is powered, an external power supply voltage (VDD) and provided with a voltage regulator (8) generating a regulated voltage (VREG) and with at least one voltage domain (6) powered by the regulated voltage. The electronic circuitry has a power supply management core (10), always powered by the external power supply voltage and which controls the voltage regulator to selectively interrupt the power supply of the voltage domain to implement: a first power-down condition wherein the voltage regulator is disabled; and a second power-down condition wherein the voltage regulator is enabled to power the aforementioned voltage domain through the regulated voltage, the first and the second power-down conditions being associated with absence of data acquisition by the sensor device. The power supply management core automatically enables the first or second power-down condition upon a first power-on of the sensor device, as a function of a configuration signal (Sconf), programmable, for example, during a factory calibration step.