MRD Series: Coreless Current Sensors with TMR Elements Designed for Photovoltaic Inverters and Power Conditioning Systems

27 June 2022 - 0 Comments

Murata has announced the new MRD series of open-loop current sensors that integrates high-performance tunnel magneto-resistive (TMR) elements - enabling precision measurement with regard to both DC and AC currents up to 40A, along with maintaining stable characteristics across an extensive temperature range. Designed for industrial systems, these sensors feature full-scale output accuracy of ±1.0% when operating anywhere between −40°C and 105°C, with fast-response time of 0.5µs. With high accuracy current sensing capabilities, these devices are suitable for a wide variety of applications like photovoltaic inverters, DC-DC converters, EV charging infrastructure and power conditioning systems.

These MRD current sensors are compliant with the UL62368-1 electrical equipment safety standard and are supplied in SOICW16 packages. 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.

Features

High-speed response Typ 0.5 µsec (bandwidth: 1 MHz)
High overall accuracy Typ 1.0%
Differential method for canceling external magnetic fields
Possible to select the bandwidth with a capacitor
Analog output
With thermal shutdown circuit
Complies with the UL62368-1 safety standards
SOICW16 package (10.3 × 10.2 × 2.8 mm)
Power supply voltage: 3.0 V and 5.0 V
Measurement range: AC (−25 to +25 A or −40 to +40 A) and DC (0 to 25 A or 0 to 40 A)

Applications

Amount of power generated by solar panels
Amount of AGV battery remaining
Amount of charging in charging stations
Amount of battery remaining in home appliances, tools, electric bicycles, and other products
Motor control and overcurrent detection