ams AG (Unterpremstaetten, Austria) has introduced a reference design board which measures current to an accuracy of ±1% by monitoring the voltage drop across a copper track on a PCB. The development of the new technique, which uses the ams AS8510 data-acquisition front end, enables designers of Battery Management Systems (BMS) to reduce bill-of-materials cost by eliminating the precision shunt resistor normally used in current-sensing applications. A precision resistor with low temperature drift can typically cost as much as $1.50 in volume. Features include:
• A blueprint for the current measurement function in a BMS, and can be applied in e-bikes, pedelecs and other applications drawing current of up to 40A.
• The ability to measure currents of up to 100A using only the resistance of a PCB’s copper track.
• The ability to produce current measurements accurate to ±1% over its entire operating temperature range (-40°C to +125°C).
For more information on the AS8510 data acquisition front end reference design, visit www.ams.com.