Power Management Switching Regulator Step-Down (Buck) Regulators Internal Power Switch Buck
Power Management Switching Regulator Step-Down (Buck) Regulators High Input Voltage Buck

LT3686A - 37V/1.2A Step-Down Regulator in 3mm × 3mm DFN and MSE

Features

  • Wide Input Range:
    Operation from 3.6V to 37V
  • Overvoltage Lockout Protects Circuit Through 60V Transients
  • Low Minimum On-Time: Converts 16VIN to 3.3VOUT at 2MHz
  • 1.2A Output Current
  • Adjustable Frequency: 300kHz to 2.5MHz
  • Constant Switching Frequency at Light Loads
  • Can Be Synchronized to External Clock
  • Tracking and Soft-Start
  • Precision UVLO
  • Short-Circuit Robust
  • IQ in Shutdown <1μA
  • Internally Compensated
  • Thermally Enhanced eMSOP and 3mm × 3mm DFN Packages

Typical Application

LT3686A Typical Application
LT3686A Typical Application

Description

The LT3686A is a current mode PWM step-down DC/DC converter with an internal power switch. The wide input range of 3.6V to 37V makes the LT3686A suitable for regulating power from a wide variety of sources, including 24V industrial supplies and automotive batteries. Its high maximum frequency allows the use of tiny inductors and capacitors, resulting in a very small solution. Operating frequency above the AM band avoids interfering with radio reception, making the LT3686A particularly suitable for automotive applications.

Cycle-by-cycle current limit, thermal shutdown and DA current sense provide protection against fault conditions. Soft-start and frequency foldback eliminate input current surge during start-up. An optional internal regulated active load at the output via the BD pin keeps the LT3686A at full switching frequency at light loads, resulting in low, predictable output ripple above the audio and AM bands. Internal compensation and an internal boost diode reduce external component count.

The LT3686A offers external synchronization capability, whereas the LT3686 does not.

Packaging

For complete and up to date package information and drawings, please refer to our packaging page

MS-10, DFN-10

LT3686A Package Drawing
LT3686A Package Drawing

Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LT3686AEDD#PBF DFN 10 E $3.57 $2.50 View
LT3686AEDD#TRPBF DFN 10 E $2.56 View
LT3686AEMSE#PBF MSOP 12 E $3.71 $2.60 View
LT3686AEMSE#TRPBF MSOP 12 E $2.66 View
LT3686AHMSE#PBF MSOP 12 H $4.49 $3.14 View
LT3686AHMSE#TRPBF MSOP 12 H $3.20 View
LT3686AIDD#PBF DFN 10 I $3.97 $2.78 View
LT3686AIDD#TRPBF DFN 10 I $2.84 View
LT3686AIMSE#PBF MSOP 12 I $4.13 $2.89 View
LT3686AIMSE#TRPBF MSOP 12 I $2.95 View
LT3686EDD#PBF DFN 10 E $3.57 $2.50 View
LT3686EDD#TRPBF DFN 10 E $2.56 View
LT3686HDD#PBF DFN 10 H $4.33 $3.03 View
LT3686HDD#TRPBF DFN 10 H $3.09 View
LT3686IDD#PBF DFN 10 I $3.97 $2.78 View
LT3686IDD#TRPBF DFN 10 I $2.84 View
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* 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 Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology demo boards are offered free of charge to qualified customers. Contact your local sales office or distributor to request a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC1647A LT3686AEDD Demo Board $100.00
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Click here to view our complete list of demo boards

Applications

  • Automotive Systems
  • Battery-Powered Equipment
  • Wall Transformer Regulation
  • Distributed Supply Regulation

Simulate

LTspice IV is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. To download LTspice IV and other FREE simulation tools, please visit our Design Simulation page.

To launch a ready to run LTspice demonstration circuit for this part:

  • Step 1: If you have not installed LTspice on this computer, download and install LTspice IV
  • Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
  • Step 3: If LTspice IV does not automatically open after clicking the link above, 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

To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.

Related models available in LTspice IV
LT3686
LT3686A

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