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Overview
Features and Benefits
- Triple, 120° Phased Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
- Configurable as a 180° Dual Phase Controller Plus a Single Phase Controller
- The Third Phase Can Regulate Up to a 13.5V Output
- High Efficiency: Up to 92%
- RSENSE or DCR Current Sensing
- ±0.75% 0.8V Output Voltage Accuracy
- Phase-Lockable Fixed Frequency 250kHz to 750kHz
- Supports Pre-Biased Outputs
- Dual N-Channel MOSFET Synchronous Drive
- Wide VIN Range: 4.5V to 24V Operation (28V Abs Max)
- Adjustable Soft-Start Current Ramping or Tracking
- Foldback Output Current Limiting
- Output Overvoltage Protection
- Dual Power Good Output Voltage Monitors
- 40-Lead 6mm × 6mm QFN Package
Product Details
The LTC3853 is a high performance triple output stepdown switching regulator controller that drives all Nchannel synchronous power MOSFET stages. Power loss and supply noise are minimized by operating the output stages out of phase. The part can be configured as a dual phase controller plus a single phase controller if needed. The part can also be configured to provide a single 3-phase output for even higher output currents.
A wide 4.5V to 24V (28V maximum) input voltage supply range encompasses most battery chemistries and intermediate bus voltages. Phase 3 can regulate output voltages up to 13.5V. A constant-frequency current mode architecture allows for a phase-lockable frequency up to 750kHz.
Independent TK/SS pins for each output ramps the output voltages and can be configured for coincident or ratiometric tracking. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The MODE/PLLIN pin selects among Burst Mode® operation, pulse-skipping or continuous inductor current modes.
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)
Documentation
Reliability Data (1)
Evaluation Kit Manuals (2)
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:
Reference Materials
Voltage vs. Current Mode Control Curent Sharing in a PolyPhase DC/DC...
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.
Discussions
LTC3853 Discussions
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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.
