TIDUEY6 April 2021
The gate driver module is built using UCC5870-Q1 isolated gate driver. The UCC5870-Q1 device is a functional safety compliant, isolated, highly configurable single channel gate driver targeted to drive high power SiC MOSFETs and IGBTs in EV/HEV applications. Power transistor protections such as shunt resistor based over-current, NTC based over-temperature, and DESAT detection, including selectable soft turn off or two-level turn off during these faults are available. It is capable of sourcing and sinking 15 A of gate drive current, supporting highly capacitive high current, high voltage power switches and also integrates a 4A active Miller clamp during switching, and an active gate pull-down while the driver lost power. The gate driver operation mode and protection functionality is programmed at power-up via SPI by C2000 MCU. It uses SPI for verification, supervision, and diagnosis as well. Since there is a higher integration of diagnostics and detection functions, it simplifies the design of ISO 26262 ASIL D compliant systems.
The design of gate driver board is based on UCC5870QDWJEVM-026 Evaluation Module User’s Guide. Detailed design information is available in this user guide. Due to the compact form factor of power module, all gate drivers are designed into a single board to optimize the trace lengths while ensuring appropriate and safe spatial distances between each driver stage as shown in Figure 3-22.
Interface to MCU is done through a 3x10 header that links the PWM, SPI signals from MCU to UCC5870s and nFLT signals from UCC5870s to MCU. As the size of gate driver board is restricted, a separate power supply module is designed to cater to isolated power supply requirements of the secondary side of gate drivers. This power supply module is mounted on the rear side of gate driver board on its headers J2, J4, J4_x and two additional headers (J3, J6) for mechanical support to make the gate driver module.
The gate driver module is mounted on inverter mother board socket headers J1, J3, J6, J10, J13, J15, J18 and J19.