Current sensing and coulomb counting
Infineon’s current sensing solutions are tailored for
- accurate state of charge (SOC) measurement
- fast over current detection (OCD), by coulomb counting in battery management systems.
The SoC curve of lithium-ion battery is almost flat, because it's highly sensitive to the cell's voltage, temperature and age. A subtle change of the voltage indicates a significant increase or decrease of SoC. Therefore, coulomb counting is a much reliable method to measure SoC.
The current sensor triggers the battery protection unit to disconnect the loads from the battery cells. OCD events must be detected and disconnected in less than few microseconds to protect the passengers, the load and the battery from a thermal runaway event.
Shunt Resistor Sensing ICs:
- Fully integrated programmable embedded system for battery monitoring and management
- Arm® Cortex® M0+ processor running at up to 48 MHz
- Programmable and reconfigurable analog and digital blocks
- Memory: 128 KByte of code flash with ECC protection.
> PSoC™ 4 HV PA family is offered in a 32-QFN package with wettable flanks
Hall sensors:
Automotive XENSIV™ TLE4972
- Magnetic coreless current sensor: an analogue sensor signals proportional to the measured current as well as two fast overcurrent detection pins.
- Robust against stray fields and suited for current measurements in EMC prone environments, due to differential measurement principle. e.g. in-phase current sensing in a motor application.
- Superior stability over temperature and lifetime: The digitally assisted analogue concept supported by proprietary stress and temperature compensation and the well-established and robust Hall technology.
Avoids negative effects (saturation, hysteresis) by core-less design: Common issue of sensors using iron cores for flux concentration.
