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LTC7851
Quad Output, Multiphase Step-Down Voltage Mode DC/DC Controller with Accurate Current Sharing
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Overview
Features and Benefits
- Operates with Power Blocks, DrMOS or External Gate Drivers and MOSFETs
- Voltage Mode Control with Accurate Current Sharing
- ±0.75% 0.6V Voltage Reference
- Quad Differential Output Voltage Sense Amplifiers
- Multiphase Capability
- Phase-Lockable Fixed Frequency 250kHz to 2.25MHz
- Lossless Current Sensing Using Inductor DCR or Precision Current Sensing with Sense Resistor or DrMOS with Integrated Current Sensing
- VCC Range: 3V to 5.5V
- VOUT Range: 0.6V to VCC – 0.5V
- Power Good Output Voltage Monitor
- Output Voltage Tracking Capability with Soft-Start
- Available in 58-Lead 5mm × 9mm QFN Package
Product Details
The LTC7851/LTC7851-1 are quad output multiphase synchronous step-down switching regulator controllers that employ a constant frequency voltage mode architecture. They maintain excellent current balance between channels when paralleled with their internal current sharing loop. Lossless DCR or a low value RSENSE is used for output current sensing. Multiple LTC7851/LTC7851-1 devices can be used for high phase count operation.
A very low offset, high bandwidth error amplifier, combined with remote output voltage sensing, provides excellent transient response and output regulation. The LTC7851/ LTC7851-1 operates with a VCC supply voltage from 3V to 5.5V and is designed for step-down conversion with VIN from 3V to 27V and produces an output voltage from 0.6V to VCC – 0.5V.
The LTC7851-1 is identical to the LTC7851 except it has a lower current sense amplifier gain, making it ideal for DrMOS devices with internal current sense.
Applications
- High Current Distributed Power Systems
- DSP, FPGA and ASIC Supplies
- Datacom, Telecom and Computing Systems
Product Categories
Markets and Technologies
Product Lifecycle
Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (3)
Documentation
User Guides (1)
Tools & Simulations
LTspice
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
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:
Reference Materials
Solutions Bulletins & Brochures (1)
Videos (1)
LTC7851 Video Product Brief
Press Releases (1)
Design Resources
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.
Support & Discussions
LTC7851 Discussions
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.
Sampling:
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Evaluation Boards
Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.