Overview

Features and Benefits

  • Dual, 180° Phased Controllers Reduce Required
  • Input Capacitance and Power Supply Induced Noise
  • High Efficiency: Up to 95%
  • RSENSE or DCR Current Sensing
  • ±1% 0.8V Output Voltage Accuracy
  • Phase-Lockable Fixed Frequency 250kHz to 780kHz
  • Supports Pre-Biased Output
  • Dual N-Channel MOSFET Synchronous Drive
  • Wide VIN Range: 4V to 24V (30V for LTC3850I) Operation
  • Adjustable Soft-Start Current Ramping or Tracking
  • Foldback Output Current Limiting
  • Output Overvoltage Protection
  • Power Good Output Voltage Monitor
  • 28-Pin 4mm × 4mm, 4mm × 5mm QFN and Narrow SSOP Packages

Product Details

The LTC3850 is a high performance dual synchronous step-down switching regulator controller that drives all N-channel power MOSFET stages. A constant-frequency current mode architecture allows a phase-lockable frequency of up to 780kHz. Power loss and supply noise are minimized by operating the two controller output stages out of phase.

OPTI-LOOP® compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3850 features a precision 0.8V reference and a power good output indicator. A wide 4V to 24V (28V maximum/30V for LTC3850I) input supply range encompasses most battery chemistries and intermediate bus voltages.

Independent TK/SS pins for each controller ramp the output voltages during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The MODE/PLLIN pin selects among Burst Mode® operation, pulse-skipping mode, or continuous inductor current mode and allows the IC to be synchronized to an external clock.

The LTC3850 is available in low profile 28-pin 4mm x 4mm, 4mm x 5mm QFN and narrow SSOP packages.


Features
LTC3850 SSOP-28 and QFN-28 Packages
LTC3850-1 ILIM function replaced with an EXTVCC function, SSOP-28 package only
LTC3850-2 The LTC3850-2 is identical to the LTC3850-1 SSOP-28, except they have different pin-outs

Applications

  • Notebook and Palmtop Computers
  • Portable Instruments
  • Battery-Operated Digital Devices
  • DC Power Distribution Systems


Product Lifecycle icon-recommended 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 (6)

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.

LTspice

Models for the following parts are available in LTspice:

LTC3850
LTC3850-1
LTC3850-2

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.

LTPowerCAD

Design tools for the following parts are available in LTpowerCAD:

LTC3850
LTC3850 Parallel
ltc3850Parallel

Product Recommendations

LTC3850 Companion Parts

Recommended Related Parts

Recommended Suggested Oscillator

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

LTC3850 Didn't find what you were looking for? Ask the Analog community »

Sample & Buy

Sample & Buy functionality exists in desktop site
Back
Check Inventory


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.


Price Table Help

 

Evaluation Boards Pricing displayed is based on 1-piece.
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.