Optical Particle Sensor ASIC Switching for Low-Power Detection

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Solution Overview

Problem

The high power consumption of optical particle sensors in mobile devices, particularly due to the continuous operation of application-specific integrated circuits (ASICs), significantly reduces battery life and hampers the integration of these sensors into mobile platforms for environmental and health monitoring applications.

Innovation Solution

The implementation of various ASIC designs that include analog-to-digital converters, digital delay circuits, and processor modules to enable power-hungry components only during particle detection, utilizing low-power modes for the majority of the time, and employing two ADCs with different resolutions to optimize power usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the ASIC operates continuously in active state for particle detection, then the detection reliability is improved, but the power consumption increases significantly

Engineering Contradiction:

Improvedetection reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The ASIC dynamically transitions between active and low-power states based on detection needs. The system activates the full ASIC functionality only when particles are detected, and switches to low-power mode during idle periods, making the operational state adaptable rather than static.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The ASIC employs periodic sampling and intermittent activation rather than continuous operation. The system performs detection operations at specific intervals and remains in low-power state between sampling periods, reducing overall energy consumption while maintaining detection capability.

Inventive Principle:

Principle #19Periodic action

2Measurement precision

If high-resolution ADCs are used for accurate particle detection, then the measurement precision is improved, but the power consumption increases

Engineering Contradiction:

Improvedetection precisionVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The detection system is segmented into multiple ADCs with different resolution levels. A first ADC with lower resolution handles routine sampling, while a second ADC with higher resolution is activated only when higher precision is needed, dividing the detection task across different computational resources.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically changes the resolution parameter of the ADC based on detection requirements. During normal operation, a lower resolution is used to minimize power consumption, and the resolution is increased only when particle detection accuracy becomes critical.

Inventive Principle:

Principle #35Parameter changes

3Duration of action of moving object

If the sensor operates continuously for environmental monitoring, then the monitoring coverage is improved, but the battery life decreases

Engineering Contradiction:

Improvemonitoring coverageVSAvoidbattery life

Core Design Contradiction:

Duration of action of moving objectVSDuration of action of stationary object

Solution Approach 1:

The sensor system employs periodic sampling rather than continuous monitoring. It activates the detection functions at scheduled intervals and remains in low-power state between sampling events, maintaining environmental monitoring coverage over extended periods while conserving battery energy.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system maintains continuous monitoring capability through periodic measurements that collectively provide comprehensive environmental coverage over time. The useful detection action continues across multiple sampling intervals, ensuring no significant events are missed while minimizing energy consumption during idle periods.

Inventive Principle:

Principle #20Continuity of useful action

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

This approach significantly reduces power consumption, extending battery life and enabling the integration of optical particle sensors into mobile devices for continuous environmental monitoring while minimizing power usage.

Implementation Method 1

an optical detector to receive a signal in response to scattered light from a particle

Methodology Applied

Scientific EffectLight scattering: Scattering

Data Source

PatentUS11353390B2Methods to reduce power consumption of an optical particle sensor via an ASIC design

Publication Date: 2022.06.07 APPLE INC

AI summary

A portable communication device includes one or more optical detectors to generate an analog signal in response to a change in an intra-cavity or an emitted optical power of a light source due to light backscattered from a particle and an application-specific integrated circuit (ASIC). The particle is illuminated via a light source. The ASIC includes an analog-to-digital converter (ADC) circuit, a digital delay circuit, a particle detector module and a processor. The ADC converts the analog signal to a digital signal. The digital delay circuit can store the digital signal for a predetermined or dynamically variable time interval. The particle detector module can analyze the digital signal and can generate an enable signal upon detecting a particle signature in the digital signal. The processor is coupled to the digital delay circuit and can start processing the digital signal in response to the enable signal.