Alternative Parts
Overview
Features and Benefits
- Single Inductor Allows VIN Above, Below, or Equal to Regulated VOUT
- VIN Range 2.8V (Need EXTVCC > 6.4V) to 80V
- VOUT Range: 1.3V to 80V
- Quad N-Channel MOSFET Gate Drivers
- Synchronous Rectification: Up to 98% Efficiency
- Input and Output Current Monitor Pins
- Synchronizable Fixed Frequency: 100kHz to 400kHz
- Integrated Input Current, Input Voltage, Output Current and Output Voltage Feedback Loops
- Improved Light Load Transition from DCM to FCM
- Improved IMON_OUT, IMON_IN Offset When Cold
- Clock Output Usable To Monitor Die Temperature
Product Details
The LT8705A is a high performance buck-boost switching regulator controller that operates from input voltages above, below or equal to the output voltage. The part has integrated input current, input voltage, output current and output voltage feedback loops. With a wide 2.8V to 80V input and 1.3V to 80V output range, the LT8705A is compatible with most solar, automotive, telecom and battery-powered systems. The LT8705A is an improved pin compatible version of the LT8705 and is recommended for new designs. See LT8705A vs LT8705 in the Applications Information section for more information.
The LT8705A includes a MODE pin to select among Burst Mode® operation, discontinuous or continuous conduction mode at light loads. Additional features include a 3.3V/12mA LDO, a synchronizable fixed operating frequency, and onboard gate drivers.
LT8705 | |
LT8705A | Improved, pin-to-pin compatible version of LT8705. Recommended for all new designs |
Applications
- High Voltage Buck-Boost Converters
- Input or Output Current Limited Converters
Product Categories
Product Lifecycle
Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Documentation & Resources
-
R530 Reliability Data3/26/2018
-
80V to 150V Non-Isolated DC/DC2/6/2018
-
High Voltage Non-Isolated Devices1/5/2018
-
LT8705 - 80V Sync Buck-Boost2/25/2013
Tools & Simulations
LTspice
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.

Models for the following parts are available in LTspice:
LTpowerCAD
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
To open the project file for this circuit:
Step 1: Download and install LTpowerCAD on your computer.
Step 2: Click on the link(s) in the section below to download part-specific project files.
Step 3: If the project file doesn't run, right-click the link and select "Save Target As." Then start the LTpowerCAD tool and open the project file by selecing "Open Project" from the "File" menu.

LTpowerCAD Project Files
Design tools for the following parts are available in LTpowerCAD:
Product Recommendations
LT8705A Companion Parts
Design Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.
PCN-PDN Information
Select a model from the dropdown below to subscribe to PCN/PDN notifications and view past notifications as well.
Support & Discussions
LT8705A Discussions
Sample & Buy
Ordering FAQs
See our Ordering FAQs for answers to questions about online orders, payment options and more.
Buy Now Pricing
(**) Displayed Buy Now Price and Price Range is based on small quantity orders.
List Pricing
(*)The 1Ku list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
Lead Times
Please see the latest communication from our CCO regarding lead times.
Sampling
Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.
Evaluation Boards
Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.