Microchip and Navitas demonstrate direct 800V-to-6V GaN converter

Microchip Technology and Navitas Semiconductor have developed a reference design that converts an 800V DC input directly to a 6V output for high-density AI computing systems. The design combines Microchip’s dsPIC33AK digital signal controller and TA100 hardware security device with sixteen Navitas NV6034 650V GaNFast power ICs. It operates at a switching frequency of 1MHz and is intended to reduce the number of conversion stages between a data-centre DC bus and the low-voltage rails supplying accelerator hardware. Microchip and Navitas report peak efficiency of up to 96% at full load and power density of 2,100W/in³. These are supplier-reported figures for the reference platform and will depend on the final system configuration and operating conditions. The dsPIC33AK controller provides the real-time control functions used to regulate the converter. Microchip’s TA100 device adds a hardware root of trust that can support authentication, secure boot and protection of stored credentials. Navitas’ NV6034 is a 650V GaN power IC with a specified on-resistance of 17mΩ. Sixteen devices are used in the reference design to handle the high-voltage switching stages. Moving directly from an 800V distribution bus to 6V is intended to replace intermediate conversion stages normally used to step the voltage down progressively. The approach can reduce the number of converters, connectors and busbars in the power path, although it also places demanding isolation, control, protection and thermal requirements on the main converter. The companies have made the reference board, software and supporting design documentation available for evaluation. The platform is being demonstrated at the Open Compute Project Global Summit.