Isabellenhütte's latest current-measurement system has two independent channels



ICB-M current sensor from Isabellenhütte

Compact size, clear cost savings and high-precision, redundant current measurement for consistently efficient energy control – the ICB-M current sensor from Isabellenhütte satisfies the key battery management criteria for future-proof vehicle design. Using its many years of experience in battery management for electric and hybrid vehicles, Isabellenhütte has developed this current measurement system for batteries in alternative drive concepts. The new ICB-M features two mutually independent measurement channels, which are galvanically isolated and have a separate power supply, setting it apart from the competition.

The first channel, a high-precision current sensor, ensures high measurement accuracy through direct shunt-based measurement. The measurement values are determined within a 24-bit range. The current sensor features an output rate of 1 kHz. CAN 2.0 is used for communication, with a data rate of up to 1 Mbit/s. A CAN Database Container (DBC) facilitates rapid system integration. The ICB-M provides a digital measurement channel (Channel 1) as well as an analogue Channel 2, completely galvanic isolated from the first, that relies on a magnetic measurement method and analyses the magnetic field generated by the current flow in the conductor, providing a voltage-level output in a measurement range of +/- 300 amperes.

Redundancy offers advantages
The ICB-M makes current measurement safer, even in the event of malfunction. The two measurement channels provide redundancy in the system – the variable to be measured can be calculated in different ways. When one channel drops out, the missing measurement value can still be ascertained with the alternative channel. “The ICB-M makes a higher level of safety possible than conventional current measurement modules. A downstream integrated safety functionality makes it possible to achieve ASIL C,” according to Jens Hartmann, Sales Director ISAscale at Isabellenhütte. The redundancy enables on-board diagnostics (OBD) and also has cost benefits versus selective solutions. A second measurement system must be integrated to ensure that conventional sensor modules have room for error. But the affordable ICB-M comes with this included, eliminating the cost of an additional measurement system to ensure redundancy.

ICB-M technical data
min. max.
Shunt-based measurement channel
Power supply 4.5 V 26.0 V (type 12.0 V)
Current 40 mA 100 mA
Current measurement range -300 A +300 A
Current accuracy -0.5% +0.5%
Temperature measurement range -40 °C +125 °C
Temperature measurement unit 0.1 °C
Operating temperature -40 °C +105 °C

Magnetic measurement channel
Power supply 4.5 V 5.5 V (type 5.0 V)
Current 7.0 mA 12.0 mA (type 9.5 mA)
Current measurement range -300 A +300 A
Current accuracy -15% +15%
Current measuring sensitivity 5.0 mV/A
Operating temperature -40 °C +105 °C

Isabellenhütte Heusler