RSB: High Power Silicon-Carbide Switching

RSB is a high power and high frequency AC solid-state switching solution for compact switching of high-power audio and microwave/radar signals. Traditional solutions use mechanical switching, which is slow, bulky and unreliable. Hexabitz developed an innovative solution for our customer to greatly reduce size while allowing solid-state switching of 600V/100A AC signals with minimum loss and leakage.

Silicon Carbide (SiC) MOSFETs are currently the darlings of the EV industry due to their high switching voltages and currents. This makes them ideal replacements for traditional mechanical switching in our application. MOSFETS, however, are only designed for DC applications, and when used with high-frequency AC signals, they have high current leakages rendering them basically useless. Hexabitz came up with innovative solution to solve this problem and reduce leakage to a minimum, basically making an ideal switch out of standard high-power SiC MOSFETs. This technique can be used for all high-power, high-frequency switching applications such as in audio, radar and 5G wireless telecommunications.

Project Skills

  • PCB Design
    • 8-layer, high-current, 2oz copper PCB
    • Silicon Carbide (SiC) MOSFETs and gate drives
    • Multiple 32-but MCUs with fine-pitch components
  • Firmware
    • High-reliability control and monitoring of each MOSFET switch
    • Monitoring currents and voltages at all input and output terminals
    • Command Line Interface for in-field configuration and testing
    • CANbus networking
    • Advanced diagnostics

Innovative Solutions

Challenge: Traditional AC power mechanical switching is slow, bulky, expensive and unreliable for customer application

Hexabitz developed a compact solid-state switching solution using high-power Silicon Carbide (SiC) MOSFETs, which are currently being widely implemented in the EV industry. Our solution can switch 120kW of power within 1200 cm2 (30x40cm) area

Challenge: MOSFETs are designed for DC switching. They exhibit high current leakages with high-frequency AC signals

Solution: Hexabitz developed an innovative proprietary solution to minimize leakage to a minimum, basically making an ideal switch out of standard high-power SiC MOSFETs

Challenge: Traditional heavy-copper PCBs cannot be manufactured with tight tolerances required for fine footprints of advanced Microcontrollers. Thus, you cannot combine high power signals and advanced digital electronics on same PCB

Solution: Hexabitz developed an innovative solution to combine both high-current capability (100A per trace) and fine-pitch manufacturing tolerances (6/4mil traces and spacing) on same PCB. Instead of building heavy-copper solution with 8 or 10oz copper to carry out the high current, we split all high-current traces into 8-layers of vertically-integrated 2oz traces which support much smaller manufacturing tolerances allowing for fine-pitch microprocessors to be included on same PCB