The ADI LTC7890/1 Synchronous Step-Down Controllers support an internal smart bootstrap switch that prevents overcharging of the BOOST pin to SW pin high-side driver supplies during dead times, protecting the gate of the top GaN FET. Additionally, the LTC7890/1 internally optimizes the gate driver timing on both switching edges to deliver smart near-zero dead times, significantly improving efficiency and allowing for high-frequency operation, even at high input voltages. The user can adjust the dead times alternatively with external resistors for margin or tailor the application.
The gate drive voltage on the LTC7890/1 precisely adjusts from 4V to 5.5V to optimize performance and enable different GaN FETs or even logic-level MOSFETs.
The LTC7890 is available in a 40-lead (6mm × 6mm), side wettable, QFN package, while the LTC7891 has a 28-lead (4mm × 5mm) side wettable, QFN package.