Sensor offers two independent signal tracks for minimal jitter as well as consistent 90° phase shift
Melexis adds the MLX92253 to its Hall-effect Dual Latch portfolio. This fast sensor offers two independent signal tracks for minimal jitter as well as consistent 90° phase shift regardless of magnet pole pitch. This enables accurate speed and direction ECU calculation as well as easy transfer across multiple platforms. This integrated solution is a choice for DC motors and encoders used in a wide range of embedded applications, including automotive, alternative mobility, consumer and industrial.
In mobility applications, directional feedback combined with linear speed, rotational speed or angular position sensing is critical for the fundamental operation and safety of countless systems. This feedback is used in passenger vehicles to monitor and limit the operation of motorised systems like window lifters, seat motors, and powered tailgates. In e-bikes, it is used to detect cadence and activate electric pedal assistance. Motor feedback also plays a crucial role in ensuring safe and precise movement, both in industry and our homes, in applications such as smart blinds and ventilation systems.
At present, engineers using a dual latch solution for stepper or DC motor applications are reliant on integrating two discrete solutions or a pitch dependent solution. In either case, designs are hindered by increased development, complicated and highly specific magnet designs, and increased costs. The MLX92253 distinguishes itself by featuring two hall plates, one Z axis and one X axis, with two independent signal tracks. It also has a common magnetic centre, which ensures a consistent 90° phase shift (quadrature) between the two speed outputs, independent of the magnet pole pitch. Furthermore, the MLX92253 features a low and narrow magnetic threshold, allowing for smaller, more affordable magnets or a larger air gap to ease assembly concerns. This functionality provides engineers with greater flexibility in their magnetic design and allows for the design to be more easily repurposed across various products.
In operation, the MLX92253 offers fast and accurate feedback with low delay, low jitter and increased reliability over traditional solutions. It features a chopping frequency of 500kHz, an operating voltage range from 2.7V to 5.5V to suit low powered embedded designs, a wide working temperature of -40 ̊C to 150 ̊C and an output state feedback during start-up. The startup feedback function can be utilised to convert the two outputs into inputs during start-up. This allows a microcontroller to retrieve the previous state of the MLX92253 before power-down, ensuring that no movement is missed.
