Overview
Features and Benefits
- Ultrawide Input Voltage Range: 3V to 100V
- Output Voltage Range: 0.8V to 60V
- Internal Synchronous Switches
- Low Ripple Burst Mode® Operation:
- 16μA IQ at 12VIN to 5VOUT Output Ripple <10mVP-P
- 7μA IQ at 48VIN to 5VOUT Output Ripple <10mVP-P
- Low Dropout: 99% Maximum Duty Cycle
- Peak Current Mode Control
- Fixed Frequency Operation: 100kHz to 1MHz
- Synchronization Input
- Programmable Undervoltage Lockout
- Power Good Flag
- Flexible Output Voltage Tracking
- Short-Circuit Protection
- Low Shutdown Current: 5μA
- Tolerates Pin Open/Short Faults
- Thermally Enhanced 20-Lead TSSOP with High Voltage Lead Spacing
Product Details
The LT8631 is a current mode PWM step-down DC/DC converter with internal synchronous switches that provide current for output loads up to 1A. The wide input range of 3V to 100V makes the LT8631 suitable for regulating power from a wide variety of sources, including automotive and industrial systems and 36V to 72V telecom supplies. Low ripple Burst Mode operation enables high efficiency operation down to very low output currents while keeping the output ripple below 10mVP-P. Resistor programmable 100kHz to 1MHz frequency range and synchronization capability enable optimization between efficiency and external component size. The soft-start feature controls the ramp rate of the output voltage, eliminating input current surge during start-up, while also providing output tracking. A power good flag signals when the output voltage is within ±7.5% of the regulated output. Undervoltage lockout can be programmed using the EN/UV pin. Shutdown mode reduces the total quiescent current to < 5μA. The LT8631 is available in a 20-lead TSSOP package with exposed pad for low thermal resistance and high voltage lead spacing.
APPLICATIONS
- Telecom Supplies
- Distributed Supply Regulation
Product Categories
Markets and Technologies
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
-
DC2110A - Demo Manual9/3/2015
-
80V to 150V Non-Isolated DC/DC2/6/2018
-
High Voltage Non-Isolated Devices1/5/2018
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.
LTspice Simulations
Models for the following parts are available in LTspice:
LT8631
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:
LT8631
Product Recommendations
LT8631 Companion Parts
Recommended Related 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.
| Part Number | Material Declaration | Reliability Data | Pin/Package Drawing | CAD Symbols, Footprints & 3D Models |
|---|---|---|---|---|
| LT8631EFE#PBF | Material Declaration | Reliability Data | 20-Lead TSSOP w/ EP | |
| LT8631EFE#TRPBF | Material Declaration | Reliability Data | 20-Lead TSSOP w/ EP | |
| LT8631HFE#PBF | Material Declaration | Reliability Data | 20-Lead TSSOP w/ EP | |
| LT8631HFE#TRPBF | Material Declaration | Reliability Data | 20-Lead TSSOP w/ EP | |
| LT8631IFE#PBF | Material Declaration | Reliability Data | 20-Lead TSSOP w/ EP | |
| LT8631IFE#TRPBF | Material Declaration | Reliability Data | 20-Lead TSSOP w/ EP | |
| Wafer Fabrication Data | R530 Reliability Data |
PCN-PDN Information
Select a model from the dropdown below to subscribe to PCN/PDN notifications and view past notifications as well.
Support & Discussions
LT8631 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
A Sample link will be shown above, next to the part, only for parts that are included in our sample program. Selecting the Sample button 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.