Datasheet LTC7892 (Analog Devices)

Data Sheet LTC7892
Low I , Dual, 2-Phase Synchronous Boost Controller for GaN FETs Q
FEATURES GENERAL DESCRIPTION
 GaN Drive Technology fully Optimized for GaN FETs The
LTC®7892
is a high-performance dual boost  Output Voltage up to 100V DC-to-DC switching regulator controller that drives all  Wide V N-channel synchronous gallium nitride (GaN) field effect IN Range: 4V to 60V and Operates Down to 1V After Start-Up transistor (FET) power stages with output voltages up to 100V. The LTC7892 solves many of the challenges  No Catch, Clamp, or Bootstrap Diodes Needed traditionally faced when using GaN FETs. The LTC7892  Internal Smart Bootstrap Switches Prevent simplifies the application design while requiring no Overcharging of High-Side Driver Supplies protection diodes and no other additional external  Resistor Adjustable Dead Times components compared to a silicon metal-oxide-  Split Output Gate Drivers for Adjustable Turn-On semiconductor field effect transistor (MOSFET) solution. and Turn-Off Driver Strengths  Accurate Adjustable Driver Voltage and UVLO The Internal smart bootstrap switches prevent  overcharging of the BOOSTx pin to the SWx pin Low Operating IQ: 15μA the high-side driver supplies during dead times,  Programmable Frequency (100kHz to 3MHz) protecting the gate of the top GaN FET. The dead times  Synchronizable Frequency (100kHz to 3MHz) of the LTC7892 can optionally be optimized with  Spread Spectrum Frequency Modulation external resistors for margin or to tailor the application  40-Lead (6mm × 6mm), Side Wettable, QFN Package for higher efficiency and allowing for high-frequency  AEC-Q100 Qualified for Automotive Applications operation.
APPLICATIONS
The gate drive voltage of the LTC7892 can be precisely adjusted from 4V to 5.5V to optimize performance and  Automotive and Industrial Power Systems allow the use of different GaN FETs or even logic-level  Military Avionics and Medical Systems MOSFETs. When biased from the boost converter  Telecommunications Power Systems regulator output, the LTC7892 can operate from an input supply as low as 1V after start-up.
TYPICAL APPLICATION Figure 1. High Power, 48V Output Boost Converter Figure 2. Efficiency and Power Loss
Rev. 0; 12/24
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One Analog Wa y, Wilmington, MA 01887 -2356, U.S.A. Tel: 781.329.47 00 ©2024 Analog Devices, Inc. Al l rights rese rve d. Document Outline Features Applications General Description Typical Application Revision History Specifications Absolute Maximum Ratings Pin Configurations and Function Descriptions Typical Performance Characteristics Functional Diagram Theory of Operation Main Control Loop Power and Bias Supplies (VBIAS, EXTVCC, DRVCC, INTVCC) High Side Bootstrap Capacitor Dead Time Control (DTCA and DTCB Pins) Start-Up and Shutdown (RUN and SS Pins) Light Load Operation: Burst Mode Operation, Pulse-Skipping Mode, or Forced Continuous Mode (MODE Pin) Frequency Selection, Spread Spectrum, and Phase-Locked Loop (FREQ and PLLIN/SPREAD Pins) Output Overvoltage Protection Power Good Applications Information Inductor Value Calculation Inductor Core Selection Current Sense Selection Low Value Resistor Current Sensing Inductor DCR Current Sensing Setting the Operating Frequency Selecting the Light-Load Operating Mode Dead Time Control (DTCA and DTCB Pins) DTCx Pin Tied to Ground (Adaptive Dead Time Control) DTCx Pin connected with a resistor to GND Power FET Selection CIN and COUT Selection Single Output 2-Phase Operation Setting the Output Voltage RUNx Pins and Undervoltage Lockout Soft Start (SSx Pins) INTVCC Regulators (OPTI-DRIVE) Topside FET Driver Supply (CB) Minimum On-Time Considerations Fault Conditions: Overtemperature Protection Phase-Locked Loop and Frequency Synchronization Efficiency Considerations Checking Transient Response Design Example PCB Board Layout Checklist PCB Layout Debugging Typical Applications Related Parts Outline Dimensions Ordering Guide