LTC3631 - High Efficiency, High Voltage 100mA Synchronous Step-Down Converter
Features
- Wide Input Voltage Range: Operation from 4.5V to 45V
- Overvoltage Lockout Provides Protection Up to 60V
- Internal High Side and Low Side Power Switches
- No Compensation Required
- 100mA Output Current
- Low Dropout Operation: 100% Duty Cycle
- Low Quiescent Current: 12μA
- 0.8V ±1% Feedback Voltage Reference
- Adjustable Peak Current Limit
- Internal and External Soft-Start
- Precise RUN Pin Threshold with Adjustable Hysteresis
- 3.3V, 5V and Adjustable Output Versions
- Only Three External Components Required for Fixed Output Versions
- Low Profile (0.75mm) 3mm × 3mm DFN and Thermally-Enhanced MS8E Packages
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC3631 is a high voltage, high efficiency step-down DC/DC converter with internal high side and synchronous power switches that draws only 12μA typical DC supply current at no load while maintaining output voltage regulation.
The LTC3631 can supply up to 100mA load current and features a programmable peak current limit that provides a simple method for optimizing efficiency in lower current applications. The LTC3631’s combination of Burst Mode® operation, integrated power switches, low quiescent current, and programmable peak current limit provides high efficiency over a broad range of load currents.
With its wide 4.5V to 45V input range and internal overvoltage monitor capable of protecting the part from 60V surges, the LTC3631 is a robust converter suited for regulating a wide variety of power sources. Additionally, the LTC3631 includes a precise run threshold and a soft‑start feature to guarantee that power system start-up is well-controlled in any environment.
The LTC3631 is available in the thermally enhanced 3mm × 3mm DFN and MS8E packages.
Packaging
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
| Part Number | Package | Code | Temp | Package Drawing |
RoHS |
|---|---|---|---|---|---|
| LTC3631EDD-3.3#PBF | 3x3 DFN-8 | DD | E | 05-08-1698 | Yes |
| LTC3631EDD-3.3#TRPBF | 3x3 DFN-8 | DD | E | 05-08-1698 | Yes |
| LTC3631EDD-5#PBF | 3x3 DFN-8 | DD | E | 05-08-1698 | Yes |
| LTC3631EDD-5#TRPBF | 3x3 DFN-8 | DD | E | 05-08-1698 | Yes |
| LTC3631EDD#PBF | 3x3 DFN-8 | DD | E | 05-08-1698 | Yes |
| LTC3631EDD#TRPBF | 3x3 DFN-8 | DD | E | 05-08-1698 | Yes |
| LTC3631EMS8E-3.3#PBF | MS-8 | MS8 | E | 05-08-1660 | Yes |
| LTC3631EMS8E-3.3#TRPBF | MS-8 | MS8 | E | 05-08-1660 | Yes |
| LTC3631EMS8E-5#PBF | MS-8 | MS8 | E | 05-08-1660 | Yes |
| LTC3631EMS8E-5#TRPBF | MS-8 | MS8 | E | 05-08-1660 | Yes |
| LTC3631EMS8E#PBF | MS-8 | MS8 | E | 05-08-1660 | Yes |
| LTC3631EMS8E#TRPBF | MS-8 | MS8 | E | 05-08-1660 | Yes |
| LTC3631IDD-3.3#PBF | 3x3 DFN-8 | DD | I | 05-08-1698 | Yes |
| LTC3631IDD-3.3#TRPBF | 3x3 DFN-8 | DD | I | 05-08-1698 | Yes |
| LTC3631IDD-5#PBF | 3x3 DFN-8 | DD | I | 05-08-1698 | Yes |
| LTC3631IDD-5#TRPBF | 3x3 DFN-8 | DD | I | 05-08-1698 | Yes |
| LTC3631IDD#PBF | 3x3 DFN-8 | DD | I | 05-08-1698 | Yes |
| LTC3631IDD#TRPBF | 3x3 DFN-8 | DD | I | 05-08-1698 | Yes |
| LTC3631IMS8E-3.3#PBF | MS-8 | MS8 | I | 05-08-1660 | Yes |
| LTC3631IMS8E-3.3#TRPBF | MS-8 | MS8 | I | 05-08-1660 | Yes |
| LTC3631IMS8E-5#PBF | MS-8 | MS8 | I | 05-08-1660 | Yes |
| LTC3631IMS8E-5#TRPBF | MS-8 | MS8 | I | 05-08-1660 | Yes |
| LTC3631IMS8E#PBF | MS-8 | MS8 | I | 05-08-1660 | Yes |
| LTC3631IMS8E#TRPBF | MS-8 | MS8 | I | 05-08-1660 | Yes |
Order Info
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
sales office or authorized distributor.Demo Boards
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC1499A | LTC3631EDD Demo Board | 60V Transients, 4.5V ≤ VIN ≤ 45V, VOUT = 1.8V/3.3V/5V @ 100mA | $100.00 | |
| Buy Now | |||
Designed for Automotive and Transportation Applications
AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC3631IMS8E-3.3#PBF | MS-8 | I | $4.84 | $3.39 | Yes | |
| LTC3631IMS8E-3.3#TRPBF | MS-8 | I | $3.45 | Yes | ||
| LTC3631IMS8E-5#PBF | MS-8 | I | $4.84 | $3.39 | Yes | |
| LTC3631IMS8E-5#TRPBF | MS-8 | I | $3.45 | Yes | ||
| LTC3631IMS8E#PBF | MS-8 | I | $4.84 | $3.39 | Yes | |
| LTC3631IMS8E#TRPBF | MS-8 | I | $3.45 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- 4mA to 20mA Current Loops
- Industrial Control Supplies
- Distributed Power Systems
- Portable Instruments
- Battery-Operated Devices
- Automotive Power Systems
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Design Tools
LTspice
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To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.
Models for the following parts are available in LTspice:
LTC3631
LTC3631-3.3
LTC3631-5
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
