Melexis: Inductive & Magnetic Sensing for Robot Joints – OTV sensing Provides Off‑Axis Dual‑Track Discs and Complete Integration

II. High‑Resolution Series for Positioning Applications

Inductive Encoders

MLX90514 (16‑bit)

The MLX90514 is a new dual‑input inductive sensor interface introduced by Melexis in December 2025. It is designed for robotics, industrial, and mobile applications. Key features include:

• Dual‑input architecture: Processes signals from two coil sets simultaneously and calculates the vernier angle on‑chip. For example, in measuring both motor input and output positions in a robotic joint, the position sensing function is integrated into a single IC, reducing external circuitry and ensuring measurement synchronisation.

• Zero‑latency measurement: Provides up to 16‑bit resolution with accuracy better than 0.1° and latency below 1 µs.

• Stray field immunity: Complies with ISO 11452‑8.

• No permanent magnet required: Uses non‑contact eddy‑current principle, eliminating magnet procurement and integration effort.

• Wide adaptability: Supports coil diameters from 20 mm to 300 mm and linear stroke up to 400 mm.

• Plug‑and‑play configuration: Only limited parameters (offset compensation, linearisation) need programming for quick deployment.

• Functional safety: Supports up to SIL 2 compliance.

• Operating temperature: –40 °C to +125 °C.

Melexis also provides a free online Inductive Simulator tool to help engineers design and optimise coil layouts.

MLX90520 (22‑bit)

The MLX90520 is a 22‑bit high‑resolution inductive encoder introduced in January 2026, positioned as a benchmark product in the market. Key features:

• 22‑bit resolution: Delivers low‑noise, zero‑latency inductive position sensing for rotary and linear motion (up to 400 mm).

• Targeted at large joints: Fully meets the demand for high‑accuracy, cost‑effective position detection in robotic joints and large mechanical joints with diameters from 20 mm to 200 mm.

• Ultra‑thin module design: In large through‑shaft applications, the ultra‑thin module (IC, PCB and target, thickness <3 mm) enables more compact mechanical designs.

• Optical encoder alternative: As Melexis product line director Lorenzo Lugani stated, “With the inductive MLX90520, we offer the robotics industry a compelling alternative to optical encoders, combining high performance with competitive pricing and a straightforward development process.”

• Functional safety: Supports up to SIL 3 system‑level compliance.

• Contamination resistance: Inductive sensors inherently resist dust and other contaminants.

Together, MLX90520 and MLX90514 cover the full size range from small joints (<2 cm) to large joints (<20 cm).

Magnetic Encoder Chip – MLX90384 Arcminaxis® (18‑bit)

The MLX90384 is Melexis’ first product featuring Arcminaxis® technology, developed specifically to meet the demand for affordable, high‑precision joint position sensing. Key features:

• 18‑bit resolution: Provides up to 18‑bit resolution over the full 360° range.

• Arcminaxis® technology: Combines multi‑axis sensing with vernier technique, using a dual‑track magnet design (Master track and Nonius track).

• Magnet‑independent: A single chip works with various magnets regardless of pole pitch.

• Generous mounting tolerances: Magnet‑to‑sensor placement tolerance ±0.5 mm, nominal air gap 1.5 mm.

• Simplified assembly: Reduces assembly complexity, offering a cost‑effective solution for manufacturers.

• Complete package: Supplied with magnet, sensor, and software for a turnkey experience.

• High‑speed SPI: 6 MHz multi‑function interface.

This product targets small joints (<2 cm) and supports shaft‑end and through‑shaft sensing.