Issue link: https://resources.mouser.com/i/1429079
26 \ VISHAY An Automotive Grade Above Electric Car Battery Charging Management Battery charge management is critical to EV performance, as the battery chemistry is susceptible to temperature and the charge times are very high at the moment. Vishay addressed this opportunity with several innovative product solutions. 22KW ON-BOARD CHARGER (OBC) WITH A 3-PHASE INPUT VOLTAGE Charge time is one of the most considerable barriers to the widescale adoption of EVs. The power demand from fast charging continues to pressure delivery systems to increase OBC power from 5.5kW to 22kW. This higher level, paired with consumer desire for increased efficiency and power density at low cost, opens the door for an effective 3-phase solution. Vishay designed a high-power, 3-phase OBC that also carries a virtual neutral point to split the DC bus into two equal stages. This feature enables the use of silicon (vs. SiC) MOSFETs, protecting cost. OPTOCOUPLER TO MAINTAIN A SAFE GALVANIC ISOLATION BARRIER With the significantly higher voltages added by EV applications to the existing lower voltages, it is essential to maintain the appropriate isolation barrier to protect safety. Vishay developed a 2kW 400V/12V DC/DC converter regulated by a linear optocoupler with a phototranistor output to transfer power cost- effectively by isolating voltages between high and low sources. To ensure the desired galvanic isolation performance, engineers designed the optocoupler with a high current transfer ratio and high-isolation test voltage. Ensuring the isolation barrier is sufficient requires the system to read the different voltage levels accurately. Linear optocouplers are an effective method for measuring the isolated high and low-voltages. INTELLIGENT CURRENT SENSE AND SAFETY SWITCH (ICSS) FOR BMS AND HIGH-CURRENT LOADS As current levels continue to increase in both 48V and 12V systems, Vishay recognized the need to upgrade the traditional mechanical relays with a more intelligent solution to extend the life of the components and increase safety. The ICSS seamlessly integrates into the vehicle and turns the load on and off when needed. Like many of Vishay's components, the ICSS contains optimal cooling to minimize thermal stress damage. Engineers designed the switch with internal thresholds for current inrush, and embedded thermistors measure the MOSFET temperature and open the circuit between load and battery. These parameters provide operators a view of the health of the battery and its proximity to over-current.