LT3695 Series - 1A Fault Tolerant Micropower Step-Down Regulator

Features

  • Wide Input Range:
        Operation from 3.6V to 36V
        Overvoltage Lockout Protects Circuits
        Through 60V Transients
  • FMEA Fault Tolerant:
        Output Stays at or Below Regulation Voltage
        During Adjacent Pin Short or When a Pin Is Left Floating
  • 1A Output Current
  • Low Ripple (< 15mVP-P) Burst Mode® Operation
         IQ = 75μA for 12VIN to 3.3VOUT with No Load
  • Adjustable Switching Frequency: 250kHz to 2.2MHz
  • Short-Circuit Protected
  • Synchronizable Between 300kHz and 2.2MHz
  • Output Voltage: 0.8V to 20V
  • Power Good Flag
  • Fixed Output Voltage Versions for 3.3V and 5V Available Small, Thermally Enhanced 16-Pin MSOP Package
  Designed for Automotive and Transportation Applications
AEC-Q100 generic family data available for specific packages


Typical Application

LT3695 Typical Application
LT3695 Typical Application

Description

The LT3695 series are adjustable frequency (250kHz to 2.2MHz) monolithic buck switching regulators that accept input voltages up to 36V and can safely sustain transient voltages up to 60V. The devices include a high efficiency switch, a boost diode, and the necessary oscillator, control and logic circuitry. Current mode topology is used for fast transient response and good loop stability. A SYNC pin allows the user to synchronize the part to an external clock, and to choose between low ripple Burst Mode operation and standard PWM operation.

The LT3695 regulators tolerate adjacent pin shorts or an open pin without raising the output voltage above its programmed value.

Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 15mV in a typical application. Shutdown reduces input supply current to less than 1μA while a resistor and capacitor on the RUN/SS pin provide a controlled output voltage ramp (soft-start). Protection circuitry senses the current in the power switch and external Schottky catch diode to protect the LT3695 regulators against short-circuit conditions. Frequency foldback and thermal shutdown provide additional protection.

The LT3695 series is available in a thermally enhanced 16-pin MSOP package.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

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

Part Number Package Code Temp Package
Drawing
RoHS
LT3695EMSE-3.3#PBF MS-16E MSE E 05-08-1667 Yes
LT3695EMSE-3.3#TRPBF MS-16E MSE E 05-08-1667 Yes
LT3695EMSE-5#PBF MS-16E MSE E 05-08-1667 Yes
LT3695EMSE-5#TRPBF MS-16E MSE E 05-08-1667 Yes
LT3695EMSE#PBF MS-16E MSE E 05-08-1667 Yes
LT3695EMSE#TRPBF MS-16E MSE E 05-08-1667 Yes
LT3695HMSE-3.3#PBF MS-16E MSE H 05-08-1667 Yes
LT3695HMSE-3.3#TRPBF MS-16E MSE H 05-08-1667 Yes
LT3695HMSE-5#PBF MS-16E MSE H 05-08-1667 Yes
LT3695HMSE-5#TRPBF MS-16E MSE H 05-08-1667 Yes
LT3695HMSE#PBF MS-16E MSE H 05-08-1667 Yes
LT3695HMSE#TRPBF MS-16E MSE H 05-08-1667 Yes
LT3695IMSE-3.3#PBF MS-16E MSE I 05-08-1667 Yes
LT3695IMSE-3.3#TRPBF MS-16E MSE I 05-08-1667 Yes
LT3695IMSE-5#PBF MS-16E MSE I 05-08-1667 Yes
LT3695IMSE-5#TRPBF MS-16E MSE I 05-08-1667 Yes
LT3695IMSE#PBF MS-16E MSE I 05-08-1667 Yes
LT3695IMSE#TRPBF MS-16E MSE I 05-08-1667 Yes


LT3695 Package Drawing
LT3695 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LT3695EMSE-3.3#PBF MS-16E E $4.64 $3.25 Yes
LT3695EMSE-3.3#TRPBF MS-16E E $3.31 Yes
LT3695EMSE-5#PBF MS-16E E $4.64 $3.25 Yes
LT3695EMSE-5#TRPBF MS-16E E $3.31 Yes
LT3695EMSE#PBF MS-16E E $4.64 $3.25 Yes
LT3695EMSE#TRPBF MS-16E E $3.31 Yes
LT3695HMSE-3.3#PBF MS-16E H $5.51 $3.86 Yes
LT3695HMSE-3.3#TRPBF MS-16E H $3.92 Yes
LT3695HMSE-5#PBF MS-16E H $5.51 $3.86 Yes
LT3695HMSE-5#TRPBF MS-16E H $3.92 Yes
LT3695HMSE#PBF MS-16E H $5.51 $3.86 Yes
LT3695HMSE#TRPBF MS-16E H $3.92 Yes
LT3695IMSE-3.3#PBF MS-16E I $5.16 $3.61 Yes
LT3695IMSE-3.3#TRPBF MS-16E I $3.67 Yes
LT3695IMSE-5#PBF MS-16E I $5.16 $3.61 Yes
LT3695IMSE-5#TRPBF MS-16E I $3.67 Yes
LT3695IMSE#PBF MS-16E I $5.16 $3.61 Yes
LT3695IMSE#TRPBF MS-16E I $3.67 Yes
Buy NowRequest Samples
* 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 offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about 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
DC1519A LT3695EMSE Demo Board | Fault-Tolerant, 6.9V ≤ VIN ≤ 36/60V, VOUT = 5V @ 1A $100.00
DC1578A-A LT3695EMSE-3.3 Demo Board | Fault-Tolerant, 4.5V ≤ VIN ≤ 36/60V, Vout = 3.3V @ 1A $100.00
DC1578A-B LT3695EMSE-5 Demo Board | Fault-Tolerant, 6.9V ≤ VIN ≤ 36/60V, Vout = 5V @ 1A $100.00
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

Please contact your local sales representative for more information regarding reliability reports and AEC-Q100 data or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LT3695HMSE-3.3#PBF MS-16E H $5.51 $3.86 Yes
LT3695HMSE-3.3#TRPBF MS-16E H $3.92 Yes
LT3695HMSE-5#PBF MS-16E H $5.51 $3.86 Yes
LT3695HMSE-5#TRPBF MS-16E H $3.92 Yes
LT3695HMSE#PBF MS-16E H $5.51 $3.86 Yes
LT3695HMSE#TRPBF MS-16E H $3.92 Yes
LT3695IMSE-3.3#PBF MS-16E I $5.16 $3.61 Yes
LT3695IMSE-3.3#TRPBF MS-16E I $3.67 Yes
LT3695IMSE-5#PBF MS-16E I $5.16 $3.61 Yes
LT3695IMSE-5#TRPBF MS-16E I $3.67 Yes
LT3695IMSE#PBF MS-16E I $5.16 $3.61 Yes
LT3695IMSE#TRPBF MS-16E I $3.67 Yes
Buy NowRequest Samples
* 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.

Applications

  • Automotive Battery Regulation
  • Automotive Entertainment Systems
  • Distributed Supply Regulation
  • Industrial Supplies

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Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

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
  • Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
  • Step 3: If LTspice 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.

Models for the following parts are available in LTspice:
LT3695
LT3695-3.3
LT3695-5

Technical Support