Open-loop current sensors for industrial systems

Murata announces the MRD series of open-loop current sensors for industrial systems. Each integrates high-performance tunnel magneto-resistive (TMR) elements – enabling precision measurement with regard to both DC and AC currents up to 40A, as well as maintaining stable characteristics across an extensive temperature range. This gives them an industry-leading full-scale output accuracy of ±1.0% when operating anywhere between -40°C and 105°C, with a fast response time of 0.5μs (typical) also being supported.

The coreless structure of these current sensors does not exhibit hysteresis effects or saturation issues which are typical side-effects with an iron core. It also results in reduced size and weight, as well as making mounting easier. Their proprietary differential measurement with two TMR-based elements gives immunity against external magnetic stray fields. This makes them suitable for use in application environments with high levels of electromagnetic noise.

Because of the high accuracy current sensing capabilities of the Murata MRD series and the fast response that these devices can achieve, they will be of significant value in a wide variety of applications. These include photovoltaic inverters, DC-DC converters, EV charging infrastructure and power conditioning systems.

Murata’s MRD current sensors are compliant with the UL62368-1 electrical equipment safety standard. These devices are supplied in SOICW16 packages as well as galvanic isolation over 4.8kV.