LTC3731
PRODUCTION3-Phase, 600kHz, Synchronous Buck Switching Regulator Controller
- Part Models
- 8
- 1ku List Price
- Starting From $7.29
Overview
- 3-Phase Current Mode Controller with Onboard MOSFET Drivers
- ±5% Output Current Matching Optimizes Thermal Performance and Size of Inductors and MOSFETs
- Differential Amplifier Accurately Senses VOUT
- ±1% VREF Accuracy Over Temperature
- VOUT Range: 0.6V to 5.5V without Diffamp
- VOUT Range: 0.6V to (VCC – 1.2V) with Diffamp
- 250kHz to 600kHz 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 5mm × 5mm QFN and 36-Pin Narrow (0.209") SSOP Packages
The LTC3731 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 3-phase controller drives its output stages with 120° phase separation at frequencies of up to 600kHz 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.
A differential amplifier provides true remote sensing of both the high and low side of the output voltage at the point of load. The precision reference supports output voltages from 0.6V to 6V.
Soft-start and a defeatable, timed short-circuit shutdown protect the MOSFETs and the load. Current foldback provides protection for the external MOSFETs under short-circuit or overload conditions.
Applications
- Desktop Computers and Servers
- High Performance Notebook Computers
- High Output Current DC/DC Power Supplies
Documentation
Data Sheet 1
User Guide 4
Design Note 2
Technical Articles 2
Video 1
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 Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| LTC3731CG#PBF | 24-Lead SSOP | ||
| LTC3731CG#TRPBF | 24-Lead SSOP | ||
| LTC3731CUH#PBF | 32-Lead QFN (5mm x 5mm x 0.75mm w/ EP) | ||
| LTC3731CUH#TRPBF | 32-Lead QFN (5mm x 5mm x 0.75mm w/ EP) | ||
| LTC3731IG#PBF | 24-Lead SSOP | ||
| LTC3731IG#TRPBF | 24-Lead SSOP | ||
| LTC3731IUH#PBF | 32-Lead QFN (5mm x 5mm x 0.75mm w/ EP) | ||
| LTC3731IUH#TRPBF | 32-Lead QFN (5mm x 5mm x 0.75mm w/ EP) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Nov 18, 2019 - 19_0266 Laser Top Mark for SSOP36/44/48 Packages assembled in ADPG and UTAC |
||
| LTC3731CG#PBF | PRODUCTION | |
| LTC3731CG#TRPBF | PRODUCTION | |
| LTC3731IG#PBF | PRODUCTION | |
| LTC3731IG#TRPBF | PRODUCTION | |
|
Jan 20, 2022 - 21_0269 Addition of Alternate Assembly Site ASE Taiwan for Select LFCSP Products |
||
| LTC3731CUH#PBF | PRODUCTION | |
| LTC3731CUH#TRPBF | PRODUCTION | |
| LTC3731IUH#PBF | PRODUCTION | |
| LTC3731IUH#TRPBF | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
Can't find the software or driver you need?
Request a Driver/SoftwareHardware Ecosystem
| Parts | Product Life Cycle | Description |
|---|---|---|
| Circuit Monitors 1 | ||
| LTC2960 | RECOMMENDED FOR NEW DESIGNS | 36V Nano-Current Two-Input Voltage Monitor |
| Hot Swap Controllers 1 | ||
| LT4363 | RECOMMENDED FOR NEW DESIGNS | High Voltage Surge Stopper with Current Limit |
| Power System Management (PSM) & Sequencers 1 | ||
| LTC2974 | RECOMMENDED FOR NEW DESIGNS | 4-Channel PMBus Power System Manager Featuring Accurate Output Current Measurement |
| Switching Regulators & Controllers 1 | ||
| LTC3880 | RECOMMENDED FOR NEW DESIGNS | Dual Output PolyPhase Step-Down DC/DC Controller with Digital Power System Management |
Tools & Simulations
LTspice 1
Models for the following parts are available in LTspice:
- LTC3731
- LTC3731H
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.
Evaluation Kits
LTC3731CUH Demo Board | 3-Phase, VIN = 5V to 14V, VOUT = 1.5V/60A
Resources
LTC3731CUH (x4) | 12-Phase, 10V - 14VIN, 1.5VOUT @ 180A
Resources
LTC3731CUH (x2) | 6-Phase, 10V - 14VIN, 1.5VOUT @ 90A
Resources
LTC3731CG | 3-Phase, VIN = 9V to 14V, VOUT = 2.5V/1.8V @ 60A
Resources
LTC3738CUHF/LTC3731CUH Demo Board | 6-Phase, 8V ≤ VIN ≤ 14V, VOUT = VRM9.X / 10.X @ 120A