This page will discuss the design decisions into creating the DCDC converting using Vicors DCM3623xA5N17B4y7z DCDC converter module. It will also discuss possible changes made to a newer revision in the case of the board not meeting the power requirements of the car's low voltage systems due to efficiency.
Goals
The main goals of the DCDC converter was to regulate the battery voltage on the input terminals to about 13.5V at the maximum current out in the most efficient method possible to provide power to our low voltage systems. To do so, the design was made to be very linear, allow for adequate heat dissipation, and allow for a high current path.
Linear Design
The design of the PCB layout made sure to allow the current path to be a constant direction from left to right.
Heat Dissipation
The converter itself requires a solid heat dissipation strategy. Taiping was able ton secure some Vicor Heat sinks made for this model, that is placed on top of the DCDC module. In addition, the design included via stitching on the ground planes with large enough vias for sufficient heat sinking across the two planes. However after some initial testing, the heat of the module was starting to get over 100degreesC even with the large heatsink, so the plan is to place a large fan on top of the module in addition to the heat sink. (the heat sink module measures at
High Current Path
The module uses M8 wurth terminals on its outputs to handle the large current output form the board to power distribution. In addition, all the traces made on the board are copper pours with matched area for the + and - lines on HV in and out. A fuse is placed on the input rated for 8A and 420VAC. Due to the inrush caused by the bulk capacitors on the input, there is an ICL hacked on to the input terminal to fuse (the trace is cut) that will start at a cold state providing resistance enough so the current it limiting, then becomes hot enough that the resistance decreases significantly, and as there is no longer inrush current, there is less power loss from the ICL (Inrush Current Limiter). The next revision will have an active inrush current limiting circuit for increased efficiency, if it is noted that it is a problem.