Features and Benefits
- Sub-Milliohm DCR Current Sensing
- Operates with Power Blocks, DRMOS or External Gate Drivers and MOSFETs
- Supports Phase Shedding and N+1 Phase Redundancy
- Programmable DCR Temperature Compensation
- ±0.75% Maximum Total DC Output Error Over Temperature
- Dual Differential Remote Output Voltage Sense Amplifiers
- Phase-Lockable Fixed Frequency Range: 200kHz to 1.2MHz
- VIN Range: 4.5V to 38V
- VOUT Range: 0.6V to 3.5V
- Supports Smooth Start-Up into Pre-Biased Outputs
- Programmable Soft-Start or VOUT Tracking
- Hiccup Mode/Soft Recovery from Output Overcurrent
- 36-Lead (5mm × 6mm) QFN Package
The LTC3774 is a dual PolyPhase® current mode synchronous step-down switching regulator controller that drives power blocks, DRMOS or external gate drivers and power MOSFETs. It offers an LTC-proprietary technique that enhances the signal-to-noise ratio of the current sense signal, allowing the use of inductors with very low DC winding resistances as the current sense element for maximum efficiency and reduced jitter.
The maximum current sense voltage is programmable from 10mV to 30mV. High speed, low offset remote sense differential amplifiers and a precise 0.6V reference provide accurate output voltages between 0.6V and 3.5V from a wide 4.5V to 38V input supply range. Soft recovery from output shorts or overcurrent minimizes output overshoot. Burst Mode® operation, continuous and pulse-skipping modes are supported. The constant operating frequency can be synchronized to an external clock or linearly programmed from 200kHz to 1.2MHz. Up to six LTC3774 controllers can be paralleled for 1-, 2-, 3-, 4-, 6-, 8- or 12-phase operation.
The LTC3774 is available in a 36-lead (5mm × 6mm) QFN package.
- Computer Systems
- Telecom and Datacom Systems
- Industrial Equipment
- DC Power Distribution Systems
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 (3)
Demonstration circuit DC2111A-B features the LTC3774 in a 4-phase, high output current step-down converter with sub-mΩ DCR sensing. This high performance, high efficiency converter provides 1.2V @ 120A and operates at a switching frequency of 400kHz over an input voltage range of 10V to 14V. The 5mm × 5mm DrMOS and 0.33μH/0.325mΩ inductor provide high efficiency while supplying 30A per phase.
Demonstration circuit DC2111A-A features the LTC3774 in a 4-phase, high output current step-down converter with sub-mΩ DCR sensing. This high performance converter provides 1.2V @ 90A with N+1 MOSFET failure protection and operates at a switching frequency of 400kHz over an input voltage range of 10V to 14V. The 5mm × 5mm DrMOS and 0.33μH/0.325mΩ inductor provide high efficiency while supplying 30A per phase.
Demonstration circuit DC2002A is a dual output synchronous buck converter featuring the LTC3774EUHE. The demo board supplies two rails of 1.5V / 30A and 1.2V / 30A. The power stage for each rail consists of a 0.33μH 0.32mΩ DCR inductor with a 11mm × 11mm footprint and a 6mm × 6mm DrMOS driven by the PWM outputs of the LTC3774EUHE at a switching frequency of 400kHz.
Tools & Simulations
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.
Models for the following parts are available in LTspice:
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.
Design tools for the following parts are available in LTpowerCAD:
Technical Articles (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.
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.