A module for battery cell monitoring with CAN and DC-LIN buses

11.03.2017

We developed a module for Battery Management System (BMS) which monitors voltage and temperature of battery cells used within an electric vehicle. The module communicates with other ECUs over the CAN bus and also over the new DC-LIN network.

DC-LIN (also called DC-BUS) is a new LIN bus physical layer standardized in ISO 17987:2016. Unlike the classical LIN physical layer, the DC-LIN does not use the LIN bus wire and therefore, it is only connected by a powerline (two wires: Vbat and GND). The LIN serial communication is modulated at approx.  5 – 10 MHz on the DC powerline. The advanage of the DC-LIN is it saves cost on the wire harness.

The module is based upon a STM32F4 microprocessor and it uses NTC thermistors for measuring the temperature of the battery cells. The measurement part of the circuit is galvanically isolated from the microprocessor. Our job was to design PCB, implement basic firmware and manufacture several prototypes.