EmbeddedRelated.com
    Parts    Linear Tech / ADI LT Series Family    LT8705IUHF    LT8705IUHF#PBF
LT8705IUHF#PBF

ADILT8705IUHF#PBF

Analog Devices Inc.
Buck-Boost Regulator Positive Output Step-Up/Step-Down DC-DC Controller IC 38-QFN (5x7)
NRND235 in stock
Datasheet Digi-Key Mouser Compare Prices

Overview

The LT8705IUHF#PBF is a high-performance synchronous buck-boost DC/DC controller that operates from input voltages above, below, or equal to the output voltage. It features a wide input range of 2.8V to 80V and utilizes a four-switch architecture to provide seamless transitions between operating modes. The integrated input and output current monitoring and regulation loops make it highly suitable for complex power management tasks.

Why Choose This Part

The device offers a very wide 2.8V to 80V input and output range, minimizing the need for multiple converter stages. Its four independent regulation loops (input V/I and output V/I) provide superior control and protection for both the source and the load. Synchronous rectification ensures high efficiency, reaching up to 98 percent depending on operating conditions.

Applications

High-Power Battery Charging
Utilizing the four regulation loops to manage constant-current and constant-voltage charging for various battery chemistries from fluctuating sources.
Automotive 12V/24V Systems
Providing a stable output rail during cold crank or load dump scenarios where the input voltage may swing significantly.
Solar Powered Systems
Maximizing energy harvest from solar panels with varying output voltages while maintaining a regulated DC bus.
Telecom Power Supplies
Converting wide-range DC inputs to stable intermediate bus voltages with high efficiency.

Key Specifications

Function Step-Up/Step-Down
Topology Buck-Boost
Clock Sync Yes
Output Type Transistor Driver
Mounting Type Surface Mount
Output Phases 2
Package / Case 38-WFQFN Exposed Pad
Control Features Enable, Frequency Control, Soft Start
Number of Outputs 2
Output Configuration Positive
Frequency - Switching 100kHz ~ 400kHz
Operating Temperature -40degC ~ 125degC (TJ)
Synchronous Rectifier Yes
Supplier Device Package 38-QFN (5x7)
Voltage - Supply (Vcc/Vdd) 2.8V ~ 80V

Getting Started

Designers should begin with the DC1924A evaluation board to test the controller performance across different load conditions. Use the Analog Devices LTspice simulation tool to model the four-switch transition behavior and optimize compensation network values. Ensure careful PCB layout of the power stage to minimize parasitic inductance and handle the high current paths associated with the 80V rating.