LEM has released the first integrated current sensor on the market to provide the bitstream output of a sigma-delta converter. The latest addition to the HMSR family, the HMSR DA, was unveiled at the PCIM Europe 2022 Power Electronics Show in Nuremberg, Germany (May 10-12, 2022).
The HMSR DA delivers significant benefits in applications subject to noise, distortion and interference, confirming that LEM, a specialist in electrical measurement solutions, is the world leader in current sensor technology. The new LEM product has been created to provide a solution for industries that require clean signals and face significant challenges such as vibration, electrical noise and electromagnetic interference.
The specific advantages of a digital output current sensor include superior signal transmission and reduced noise, as well as lower cost and smaller mechanical footprint. The HMSR DA will replace much more complex and costly alternative systems that traditionally would have included a current sense resistor, a digital isolator and a power circuit. Combining all these features in a single device makes the HMSR DA a much more attractive choice for applications where compact size and low cost are paramount.
Typical applications for a digital output current sensor include stand-alone servos, robotics, sewing machines, automated guided vehicles, CNC machine tools, and a number of other applications that require high output resolution. The new HMSR DA sensor, with 11 to 13 bit resolution and 10 MHz clock speed, is LEM's first step towards an integrated digital current sensor roadmap. The company is already working on the next generation of sensors with integrated digital circuits, which will have a resolution of 14 to 16 bits and an operating frequency above 20 MHz.
Analog versions of the HMSR line of high quality inline current sensors have been in use for many years and provide power electronics designers with many benefits that the new digital model is based on. These include small sensor dimensions, high immunity to external fields, reinforced isolation and a bandwidth of 300 kHz. The HMSR family is a rugged, compact and highly accurate solution for measuring DC and AC currents in demanding switching power applications in the commercial and industrial sectors.
The market-leading and first-of-its-kind technology in the new HMSR DA digital sensor will give engineers a new way to think about how they design their systems. The output bitstream of the sigma-delta converter is not only easy to use, but also very flexible, allowing customers to apply filters to tailor the sensor to their specific needs.