Digital control algorithm tops 99% AI data centre efficiency

Navitas has developed a patented digital control for power supplies that use both GaN and SiC devices for peak efficiencies of 99.3% in AI data centre designs.

The Navitas Intelliweave digital control algorithm works with GaNFast gallium nitride (GaN) and GeneSiC silicon carbide (SiC) power semiconductors for power supply designs. It enables precision current sharing, ultra-fast dynamic response and minimal phase error via a dual-loop and dual-feed-forward interleaving control achieves absolute zero voltage switching (ZVS) across the full-load range to enable highest efficiencies.

The digital control for Critical Conduction Mode (CRM) interleaving Totem Pole Power Factor Control (PFC) enables 30% reduction in power losses compared to existing Continuous Conduction Mode (CCM) designs.

The algorithm simplifies the control complexity and maintains via a dual loop approach. The outer voltage loop is used to regulate the DC output voltage while the output of the voltage loop is assigned to the multi inner current loops. Every inner current loop regulates the average inductor current, then directly calculate theon-time of main switch, so that the current balance can be achieved. The bandwidth of inner current loop is very high and adding the feedforward coefficient enables the fast dynamic response.

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The digital control combined with high-power GaNSafe power ICs has been demonstrated on a 500 kHz GaN-based interleaving 3.2 kW CrM PFC PSU operating at 99.3% peak efficiency including EMI filter loss. Navitas has previously shown a 4.5kW design that combines GaN and SiC for AI data centre power designs.

The algorithm will be discussed later this week at the IEEE Energy Conversion Congress and Expo (ECCE) in Phoenix, Arizona.