Features and Benefits
- 3-Phase Controller with Onboard MOSFET Drivers
- Programmable Active Voltage Positioning (AVP) with True Current Sensing
- Programmable External Thermal Detection or Internal Thermal Sensing
- Precise Output Current Matching Optimizes Thermal Performance and Solution Size
- Supports Starting into Precharged VOUTS
- Differential Amplifier Accurately Senses VOUT
- PWM, Pulse Skip and Stage Shedding™ Operation
- 210kHz to 530kHz Per Phase, Fixed Frequency
- Output Power Good Indicator with Adaptive Blanking
- Adjustable Soft-Start Current Ramping
- Short-Circuit Shutdown Timer with Defeat Option
- OPTI-LOOP® Compensation Minimizes COUT
- 38-Lead (5mm × 7mm) QFN Package
The LTC3738 is a 3-phase 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 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 Pulse Skip mode technology.
The LTC3738 also allows users to program load slope via a resistor for AVP control. Both external and internal thermal sensing are available from the on-chip thermal detector and comparator.
A differential amplifier provides sensing of both the high and low sides of the output voltage.
Soft-start and a defeatable, timed short-circuit shutdown protect the MOSFETs and the load. A foldback current circuit also provides protection for the external MOSFETs under short-circuit or overload conditions. An all- “1” VID detector turns off the regulator after a 1µs timeout.
- High Performance Notebook Computers
- Servers, Desktop Computers and Workstations
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (2)
Demonstration circuits 721A-A and 721A-B are high current step-down converters for Intel VRM/VRD10 and VRM9 processor power applications. The 6-phase DC721A-A features two current-mode PolyPhaseTM controllers, the LTC3738CUHF (3-Phase Buck Controller for Intel VRM9/VRM10 with Active Voltage Positioning and the the LTC3731CUH (3-Phase, 600kHz, Synchronous Buck Switching Regulator Controller). and provides up to 120A output current. The DC721A-B is a single LTC3738 3-phase 65A output supply. The input voltage range for both demo boards is from 8V to 14V, and the output voltage is controlled by the VID setting.
Demonstration circuits 721A-A and 721A-B are high current step-down converters for Intel VRM/VRD10 and VRM9 processor power applications. The 6-phase DC721A-A features two current-mode PolyPhaseTM controllers, the LTC3738CUHF (3-Phase Buck Controller for Intel VRM9/VRM10 with Active Voltage Positioning and the the LTC3731CUH (3-Phase, 600kHz, Synchronous Buck Switching Regulator Controller) and provides up to 120A output current. The input voltage is from 8V to 14V and the output voltage is controlled by the VID setting.
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.
Sample & Buy
The USA 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. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.