LTC3731H - 3-Phase, 600kHz, Synchronous Buck Switching Regulator Controller
Features
- 3-Phase Current Mode Controller with Onboard MOSFET Drivers
- ±5% Output Current Matching Optimizes Thermal Performance and Size of Inductors and MOSFETs
- ±2% VREF Accuracy Over Temperature Up to 140°C
- Reduced Power Supply Induced Noise
- ±10% Power Good Output Indicator
- 225kHz to 680kHz Per Phase, PLL, Fixed Frequency
- PWM, Stage Shedding™ or Burst Mode® Operation
- OPTI-LOOP® Compensation Minimizes COUT
- Adjustable Soft-Start Current Ramping
- Short-Circuit Shutdown Timer with Defeat Option
- Overvoltage Soft Latch
- Adjustable Undervoltage Lockout Threshold
- Selectable Phase Output for Up to 12-Phase Operation
- Available in 36-Pin Narrow (0.209") SSOP and 5mm × 5mm QFN Packages
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC3731H is a PolyPhase synchronous step-down switching regulator controller that drives all N-channel external power MOSFET stages in a phase-lockable fixed frequency architecture. The LTC3731H is rated for operation up to 140°C junction temperature. The 3-phase controller drives its output stages with 120° phase separation at frequencies up to 680kHz per phase to minimize the RMS current losses in both the input and output filter capacitors. The 3‑phase technique effectively triples the fundamental frequency, improving transient response while operating each controller at an optimal frequency for efficiency and ease of thermal design. Light load efficiency is optimized by using a choice of output Stage Shedding or Burst Mode operation.
The precision reference supports output voltages from 0.6V to 6V. Current foldback provides protection for the external MOSFETs under short-circuit or overload conditions. Please refer to the LTC3731 data sheet for 0°C to 70°C and –40°C to 85°C rated versions.
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 |
|---|---|---|---|---|---|
| LTC3731HG#PBF | SSOP-24 | G | H | 05-08-1640 (G24) | Yes |
| LTC3731HG#TRPBF | SSOP-24 | G | H | 05-08-1640 (G24) | Yes |
| LTC3731HUH#PBF | 5x5 QFN-32 | UH | H | 05-08-1693 | Yes |
| LTC3731HUH#TRPBF | 5x5 QFN-32 | UH | H | 05-08-1693 | 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
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC3731HG#PBF | SSOP-24 | H | $5.92 | $5.00 | Yes | |
| LTC3731HG#TRPBF | SSOP-24 | H | $5.10 | Yes | ||
| LTC3731HUH#PBF | 5x5 QFN-32 | H | $7.14 | $5.00 | Yes | |
| LTC3731HUH#TRPBF | 5x5 QFN-32 | H | $5.06 | Yes | ||
| Buy Now • Request Samples | ||||||
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.Click here to view our complete list of demo boards
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 | |
|---|---|---|---|---|---|---|
| LTC3731HG#PBF | SSOP-24 | H | $5.92 | $5.00 | Yes | |
| LTC3731HG#TRPBF | SSOP-24 | H | $5.10 | Yes | ||
| LTC3731HUH#PBF | 5x5 QFN-32 | H | $7.14 | $5.00 | Yes | |
| LTC3731HUH#TRPBF | 5x5 QFN-32 | H | $5.06 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- Automotive and Industrial Power Supplies
- High Output Current DC/DC Power Supplies
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Product Notifications
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Design Tools
LTspice
LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice
Models for the following parts are available in LTspice:
LTC3731
LTC3731H
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.
