ADI LTC7891RUFDM#TRPBF

A high performance, step-down, dc-to-dc switching regulator controller that drives all N-channel synchronous gallium nitride (GaN) field effect transistor (FET) power stages from input voltages up to 100 V. Solves many of the challenges traditionally faced when using GaN FETs. Simplifies the application design while requiring no protection diodes and no other additional external components compared to a silicon metal-oxide semiconductor field effect transistor (MOSFET) solution.

The internal smart bootstrap switch prevents overcharging of the BOOST pin to SW pin high-side driver supplies during dead times, protecting the gate of the top GaN FET. Internally optimizes the gate driver timing on both switching edges to achieve smart near zero dead times, significantly improving efficiency and allowing for high frequency operation, even at high input voltages. Alternatively, the user can adjust the dead times with external resistors for margin or to tailor the application.

The gate drive voltage can be precisely adjusted from 4 V to 5.5 V to optimize performance, and to allow the use of different GaN FETs, or even logic level MOSFETs.

• GaN drive technology fully optimized for GaN FETs
• Wide VIN range: 4 V to 100 V
• Wide output voltage range: 0.8V ≤ VOUT ≤ 60 V
• No catch, clamp, or bootstrap diodes needed
• Internal smart bootstrap switches prevent overcharging of highside driver supplies
• Internally optimized, smart near zero dead times or resistor adjustable dead times
• Split output gate drivers for adjustable turn on and turn off driver strengths
• Accurate adjustable driver voltage and UVLO
• Low operating IQ: 5 μA (48 VIN to 5 VOUT)
• Programmable frequency (100 kHz to 3 MHz)
• Phase lockable frequency (100 kHz to 3 MHz)
• Spread spectrum frequency modulation
• 28-lead (4 mm × 5 mm) side wettable QFN package

• Industrial power systems
• Telecommunications power systems