Digital DC current sensors make current measurement easier

Riedon Inc offers its new SSD Smart Shunt series of highly-integrated digital SiP devices that can be employed in various battery-related current sensing applications. Each provides a 16-bit automotive-grade MCU, a 24-bit ADC (with buffered analog Inputs) and a flash memory resource. This brings plug-and-play simplicity to current measurements, battery voltage monitoring and coulomb counting. Among the places where these devices will be employed are large-scale energy storage banks, renewable energy generation infrastructure, building automation systems, industrial motor drives, EV charging stations, etc.

The original devices, launched in mid-2020, brought together the high amperage abilities of traditional passive shunt resistors and the accuracy of closed-loop Hall Effect current sensors. They offer a unique combination of accuracy, stability and electrical isolation while removing the necessity for periodic calibration work. The new series now takes this even further – providing access to more significant amounts of data and making integration more straightforward.

The internal ADC converter assists to simplify implementation significantly – allowing customer engineering teams to swiftly add high-accuracy current measurement into latest designs or retrofit this function into existing ones. There are two models to select from. The first is the RS485 serial interface, which can also be configured as MODBUS RTU, and the second is a customisable CANbus model.

Its devices have current sensing capabilities rated from 100A (2kA peak) to 1kA (20kA peak). They display better than ±0.1% full-scale accuracy, and their full-scale linearity remains within a ±0.1% margin. The advanced non-linear temperature compensation mechanisms these sensors possess provide that external temperature fluctuations do not affect their accuracy.

Long-term stability is another fundamental attribute of the series, with less than ±0.1% deviation during 1000 hours of operation (at 60C terminal temperature). A -40C to +115C (ambient) operational temperature range enables these devices to be employed in harsher environments than other current sensing products. The built-in flash memory has ECC and autocorrect on single bit errors.

These sensors are housed in packages with footprints of only 68.8mm x 80mm and have exceptionally low profiles (going down to 16.4mm). They are far smaller than equivalent current transducers available for the rated voltages offered.

“With our initial Smart Shunt current sensors proving so popular across multiple industry sectors, the new series is set to further build on this success,” states Phil Ebbert, VP of Engineering at Riedon Inc. “Customers have really valued the exceptional attributes these devices deliver in terms of accuracy, stability, non-intrusiveness, robustness, cost-effectiveness, minimal temperature drift, etc. By drawing on their feedback, we have been able to take evolutionary steps that will make Smart Shunt applicable to a much wider audience.”

Accessories include a serial connection kit that aids initial sensor setup and allows the CANbus and RS485 interfaces to connect with USB; a pre-made 1m cable and connector allows for ease of installation without special crimping tools; and an isolated base that facilitates mounting.