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Hi readers!  Hopefully, you are well and exploring technology daily. Today, the topic of our discourse is the MLX90424- integrated dual position sensors for robust security in automotive braking systems. You might already know about it or something new and different.

The MLX90424 is a highly advanced dual magnetic position sensor developed by Melexis with the stringent requirements of today's automotive braking systems, which have been highly demanding in terms of safety and performance. A combination of Hall-effect sensing and dual-sensor architecture, this device promises accurate position measurement and fault-tolerant operation, providing an excellent solution for such systems as electronic parking brakes and brake-by-wire technologies.

Melexis' Triaxis technology has been leveraged for the MLX90424, a three-dimensional magnetic field detector. It gives an accurate angular and linear position sense and has a dual-sensor configuration to ensure redundancy, providing functionality in case of failure. This configuration aligns with the ISO 26262 functional safety standards.

The sensor is designed to be highly reliable under extreme automotive conditions. It provides consistent performance over a wide range of temperatures and environmental factors. It supports digital and analog outputs for flexible integration into various automotive applications.

This article will discover its introduction, features and significations, working principles, pinouts, datasheet, and applications. Let's start.

Introduction:

• The MLX90424 is a Melexis dual magnetic position sensor designed for modern automotive braking systems that demand more stringent requirements.
• This product uses advanced Hall-effect technology to precisely measure magnetic fields, thus delivering accurate position sensing for various automotive applications.
• A dual-sensor setup provides high reliability because even if one of the sensors fails, it would not stop operation.
• It was designed to meet the safety requirements of ISO 26262 standards and is suitable for a set of critical automotive applications that include brake-bywire systems and electronic parking brakes.
• The MLX90424 is designed for durability under harsh automotive conditions; therefore, the system has a wide operating range temperature, and environmental range.
• Its dual analog and digital outputs also mean flexible integration into a diversity of automotive systems.
• The MLX90424 provides higher safety and performance for braking systems due to exceptional accuracy and durability.
• This device is also a future-oriented element in the conversion toward electric and autonomous vehicles.

Features:

Dual-Sensor Architecture for Fault-Tolerant Operation:

The MLX90424 contains a dual-sensor design, providing redundancy to prevent the failure of a single point. Such architecture is very important for automotive safety systems where a failure at one point can lead to disastrous effects.

Higher Reliability: 

Each sensor works independently. Thus, the system will be able to detect faults and will continue working even if a sensor fails.

ISO 26262 Compliance: 

The dual-sensor architecture aligns with ISO 26262 standards on functional safety, thus fitting applications demanding high reliability.

Hall-Effect Sensing Technology:

Hall-effect sensing technology is the heart of the MLX90424, which measures magnetic fields very precisely. With this, position and movement can be detected contactless.

Precision: 

The Hall-effect sensors are capable of providing high angular and linear position measurements. Systems such as brake pedals and steering mechanisms require the said precision.

Durability: 

The contactless sensing mechanism makes it less prone to wear and tear, therefore lasting longer.

Triaxis® Technology for 3D Magnetic Field Sensing:

The MLX90424 utilizes the Melexis proprietary Triaxis technology which enables it to sense a three-dimensional magnetic field (X, Y, and Z axis).

High Accuracy: 

This feature ensures accurate detection of angular and linear positions.

Versatility: 

It supports various magnetic configurations, including rotating magnets for angular sensing and moving magnets for linear sensing.

Dynamic Performance: 

The Triaxis® technology adapts to dynamic changes in magnetic fields, maintaining consistent accuracy under varying conditions.

Digital and Analog Output Support:

The MLX90424 supports multiple output interfaces for seamless integration into various systems.

Digital Outputs: 

It includes PWM (Pulse Width Modulation) and SENT (Single Edge Nibble Transmission) for accurate and high-speed data communication.

Analog Outputs: 

This provides an analog voltage signal for systems that require traditional interface compatibility.

Customization: 

Configurable output ranges and formats allow tailoring to specific application needs.

Wide Operating Range:

The MLX90424 is designed to operate faultlessly under extreme environmental conditions, which is the hallmark of automotive applications.

Range: 

It operates efficiently over a temperature range of -40 °C to +150 °C, making it ideal for applications that are subjected to extreme heat or cold conditions.

Robustness: 

Resilient to extreme conditions such as vibration and mechanical shock, as well as electromagnetic interference (EMI).

Packaging sealed: 

Durable packaging that prevents it from getting dust, moisture, and other contaminants.

Adherence to Automotive Standards:

Completely meeting the stringent automotive industry norms, the MLX90424 is reliable and safe to use.

AEC-Q100 Qualified:

Qualified to auto level, ensuring dependable performance within demanding environments.

ISO 26262 Functional Safety: 

A qualified system that meets system requirements for safety integrity levels and can be used in high-end applications like brake-by-wire as well as EPB.

Advanced Signal Processing:

The MLX90424 has integrated signal processing functionality for improved accuracy and reliability of outputs.

Noise Reduction: 

Eliminates electrical and environmental noise; this provides stable readings.

Error Compensation: 

Automatically compensates for temperature drifts and magnetic interference, guaranteeing consistent performance.

Self-Diagnostic Features: 

Tracks the functionality of the product itself and reports faults; enables proactive maintenance.

Compact and Lightweight Design:

Despite its advanced functionality, the MLX90424 is designed to be housed in space-constrained automotive systems.

Compact Form Factor: 

Perfect for integrations in applications where space is limited - EPB modules, brake actuators, etc.

Lightweight Housing: 

This contributes to a fuel-efficient system, hence helping the vehicle achieve better mileage.

Low power consumption:

The MLX90424 is energy-efficient since it is a product especially designed for today's autos that are mainly powered by batteries.

Energy-Saving Modes: 

Offers low-power modes for standby in the event when the system is idle or not in use.

Efficient Design: 

Reduces power consumption without sacrificing performance, which helps it be used in electric and hybrid cars.

Customization and Flexibility:

The sensor allows a high degree of customization in terms of adaptation to application requirements.

Configurable Settings: 

Sensitivity, output range, and response time parameters can be set for varied applications.

Multiple Magnet Configurations: 

The MLX90424 is compatible with multiple magnets, which can facilitate different designs and placements.

Increased Safety Features:

Safety is a major issue with automotive systems, and the MLX90424 has features to achieve that.

Redundancy: 

The dual-sensor setup ensures operational continuity in case of sensor failure.

Diagnostics: 

Continuous self-monitoring capabilities detect faults and provide alerts, enhancing overall system safety. hybrid vehicles.

Datasheet:

General Information:

Electrical Characteristics:

Environmental Specifications:

Key Features:

Package Information:

Working Principle:

Hall-Effect Technology:

At its core, the MLX90424 employs Hall-effect technology, which detects the presence and magnitude of magnetic fields. This principle is based on the Hall effect, where a voltage is generated perpendicular to the current flow in a conductor when exposed to a magnetic field. The strength and direction of the magnetic field alter the voltage, which is then measured to determine position.

The sensor has a dual-sensor architecture that monitors magnetic fields at two different points. This redundancy improves accuracy and ensures that the sensor continues to function even in the event of a single-sensor failure, an important requirement for safety-critical automotive applications.

3D Magnetic Field Sensing:

The MLX90424 uses Triaxis® technology that enables the sensor to detect magnetic fields in three dimensions, namely X, Y, and Z axes. This 3D sensing capability offers

Angular Position Measurement: 

In the sensor, the measurement of rotational positions is determined using changes in the angle of the magnetic field.

Linear Position Measurement: 

It also measures linear displacement in this sensor using shifts of the magnetic field's strength in a straight line.

Using these two types of measurements allows it to be used with a wide variety of brake-by-wire systems, and throttle position monitoring as an example.

Signal Processing:

The MLX90424 contains a high-performance ASIC for signal processing. The following explains the process:

Detection of the Magnetic Signal: 

The magnetic field data are detected through the two Hall-effect sensors from the magnet in the system.

Signal Conditioning: 

The detected raw magnetic signals are conditioned to eliminate noise and assure accurate measurement.

ADC: 

Through an ADC, the conditioned analog signals are converted to digital data, thereby becoming available for further processing.

Position Calculation: 

ASIC makes a highly accurate and repeatable computation of the position from digital data from a magnetic field.

Fault Tolerant Operation:

Redundant design allows dual sensor architecture, fault-tolerant operation is a vital characteristic of this application due to the critical nature of safe-critical applications, and hence the system can instantly and transparently switch from using the failing sensor.

This feature allows the MLX90424 to be ISO 26262 compliant, thereby meeting different levels of ASIL required for automotive systems.

Digital and Analog Output:

The MLX90424 is compatible with both digital and analog formats for outputs. It allows integration in either format.

PWM and SENT Protocols:

The sensor provides Pulse Width Modulation (PWM) and Single Edge Nibble Transmission (SENT) protocols for digital output.

Analog Output: 

For applications where a traditional interface is used, the sensor also offers high-accuracy analog outputs that ensure wide-ranging applicability.

Self-Diagnostics:

The MLX90424 has powerful self-diagnostic capabilities. These are critical for the maintenance of reliability in critical systems. It continuously monitors its internal circuits, signal quality, and temperature. If any fault is detected, it triggers a fault signal so corrective action can be taken on time.

Wide Operating Range:

The sensor is designed to work efficiently in aggressive environmental conditions:

Temperature Tolerance: 

It works satisfactorily at a temperature range of -40°C to +150°C, ensuring stability within hot engine compartments and low temperatures.

Resistance to External Interference: 

The sensor is highly resistant to vibrations, mechanical shock, and EMI, which makes it feasible for demanding automotive environments.

Packaging is sealed:

The MLX90424 is shielded in durable, sealed packaging such that the components will not corrode or get contaminated with dust moisture, and chemicals. They thus ensure durability for any long period, even as it operates in harsher conditions.

Magnet Integration:

The MLX90424 is designed to be used together with an external magnet, normally mounted on a moving part in the system. The relative position of this magnet to the sensor defines the characteristics of the magnetic field that is used by the sensor to make position calculations.

This design enables the sensor to be used in many different configurations, such as pedal position sensing, steering angle measurement, and brake lever motion sensing.

Functional Safety Compliance:

The MLX90424 complies with the ISO 26262 functional safety standards and is suitable for applications requiring high safety integrity levels. Its design supports:

Diagnostic Coverage: 

Continuous monitoring of internal operations and fault detection.

Redundant Architecture: 

The dual-sensor setup provides backup functionality in case of a failure.

ASIL Certification: 

The sensor can achieve ASIL levels required for critical systems, such as brake-by-wire or electronic parking brakes (EPB).

MLX90424 Pinouts:

Additional Notes:

• OUT1 and OUT2: The independent outputs that enable dual-sensor capability for fault tolerance and redundancy.

• VDD: Keep the power source in the range of 3.3V to 5.5V for the component to work properly.

• GND/VSS: All ground pins should be connected to a common ground plane to reduce electrical noise.

• Unused Pins (NC): To be left alone; do not connect or short to the circuit.

Applications: 

The MLX90424 is a versatile dual magnetic position sensor with applications spanning automotive, industrial, and safety-critical domains:

Automotive Applications:

• Brake-by-Wire Systems: The sensor gives very accurate position measurements, making possible advanced braking technologies with enhanced control and safety.

• Electronic Parking Brakes (EPB): Their fault-tolerant functionality guarantees flawless operation in the auto-parking system, compliant with demanding automotive safety regulations.

• Steering Systems: The MLX90424 serves as a core component of electric power-assisted steering (EPAS), providing accurate angle and position detection to enhance vehicle performance and stability.

• Transmission Control: Supports accurate sensing of clutch and gear positions, thereby ensuring smoother and safer operation of advanced transmission systems.

• Electric Vehicle (EV) Components: It plays a very critical role in motor position sensing, which enables accurate control of electric drivetrains. This is critical for efficiency and performance.

Industrial Applications:

• Robotics and Automation: The system provides high accuracy of joint and actuator position feedback.

• Linear and Angular Motion Detection: It is used in machinery, which requires reliable position measurement.

Safety-Critical Applications:

Compliant with ISO 26262 functional safety standards, it is appropriate for systems requiring high safety integrity.

Conclusion: 

The MLX90424 is a revolutionary game-changing dual magnetic position sensor for rising safety, precision, and reliability in modern automotive and industrial applications. Through its integrated advanced Hall-effect technology coupled with a dual-sensor architecture, it presents an unmatched fault-tolerant operation and precision. Also, the ISO 26262 functional safety compliance is satisfied; hence, this component addresses the strict demands of any safety-critical systems for brake-by-wire, EPB, etc.

With its wide operating range, the sensor can be applied in harsh environments, including extreme temperatures, vibrations, and electromagnetic interference. Its robust design, sealed packaging, and AEC-Q100 automotive-grade qualification make it a trusted choice for the most demanding conditions.

As the automotive world pushes towards electrification and automation, the MLX90424 is at the heart of powering advanced technologies such as electric power-assisted steering, drivetrain control, and also autonomous vehicle systems. There are also industrial applications for automation and robotics in cases where reliability and precision need to be guaranteed.

The MLX90424 is proof of Melexis' dedication to innovation and safety, ensuring that it holds a prime place in the future of automotive and industrial innovations.

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