The new chips, type designation MLX90421and MLX90422 complement the existing MLX90364/5/6/7 products. They basically offer similar functionality, but with some additional enhancements incorporated. Intended for use in cost-sensitive automotive applications including powertrain actuators, pedal positioning, fuel level gauges and transmission systems, though also suitable for industrial implementations, these ICs have superior capabilities in terms of functional safety and electromagnetic compliance (EMC) characteristics. They also support heightened temperature operation.
Like their magnetic sensing element, the new position sensing ICs each feature built-in data conversion and digital signal processing, as well as a programmable output stage driver. They can be configured for accurately determining position either rotationally or linearly. The MLX90421 provides a ratiometric analog or pulse width modulated (PWM) output, while the MLX90422 delivers a single edge nibble transmission (SENT) output according to SAE J2716.
Their expansive -40°C to 160°C ambient temperature range means that they can be deployed within vehicles that lack the heat dissipation normally found in engine bays, such as hybrid and full electric vehicles. With full adherence to ISO26262 functional safety guidelines, via the safety element out of context (SEooC) approach, the sensor IC supports ASIL-B level. To ensure first-time-right EMC testing, the new ICs offer similar performance to Melexis' already established MLX9037x product family. Only one test cycle is therefore required, meaning design work can be completed quicker and the associated engineering costs are kept to a minimum. The improved absolute maximum ratings (AMR), such as output protection of -18V/34V and supply protection of -18V/37V, reduces the risk of electrical overstress.
The MLX90421 and MLX90422 can be supplied with a single die in either a SOIC-8 package format or a PCB-less DMP-4. These options are backward compatible with the company’s earlier devices, thereby providing drop-in replacements. A fully redundant dual die TSSOP-16 package is also available for safety-critical situations requiring system redundancy. Further packing options will be announced in October 2021.