LT3685
Info: : PRODUCTION
searchIcon
cartIcon

LT3685

36V, 2A, 2.4MHz Step-Down Switching Regulator

Show More showmore-icon

Info: : PRODUCTION tooltip
Info: : PRODUCTION tooltip
Viewing: Part Details
arrow-icon

Not the part you were looking for?

viewall Go to Product Selection Table
file View Data Sheet (Rev.C)
Documentation View All Documentation
LTspice LT3685 - Step-Down (Buck) Regulators Download 2.44 KB LTspice LT3685 Demo Circuit - 36V, 2A, 2.4MHz Step-Down Regulator (24V to 3.3V @ 2A) Download 3.00KB
Part Models 8
1ku List Price Starting From $3.66
Features
  • Wide Input Range:
    • Operation From 3.6V to 36V
    • Overvoltage Lockout Protects Circuit through
    • 60V Transients
  • 2A Maximum Output Current
  • Adjustable Switching Frequency: 200kHz to 2.4MHz
  • Low Shutdown Current: IQ < 1µA
  • Integrated Boost Diode
  • Synchronizable Between 250kHz to 2MHz
  • Power Good Flag
  • Saturating Switch Design: 0.25Ω On-Resistance
  • 0.790V Feedback Reference Voltage
  • Output Voltage: 0.79V to 20V
  • Soft-Start Capability
  • Small 10-Pin Thermally Enhanced MSOP and (3mm x 3mm) DFN Packages
Additional Details
show more Icon

The LT3685 is an adjustable frequency (200kHz to 2.4MHz) monolithic step-down switching regulator that accepts input voltages up to 38V operating and 60V maximum. An internal overvoltage protection circuit turns off the power switch when VIN is above 38V typical (36V minimum) which then allows the part to safely withstand 60V transients. A high efficiency 0.25Ω switch is included on the die along with a boost Schottky diode and the necessary oscillator, control, and logic circuitry. Current mode topology is used for fast transient response and good loop stability. The LT3685’s high operating frequency allows the use of small, low cost inductors and ceramic capacitors resulting in low output ripple while keeping total solution size to a minimum. The low current shutdown mode 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). A power good flag signals when VOUT reaches 89% of the programmed output voltage. The LT3685 is available in 10-Pin MSOP and 3mm × 3mm DFN packages with exposed pads for low thermal resistance.

Applications

  • Automotive Battery Regulation
  • Set Top Box
  • Distributed Supply Regulation
  • Industrial Supplies
  • Wall Transformer Regulation
Show More Arrow image
file View Data Sheet (Rev.C)
Documentation View All Documentation
LTspice LT3685 - Step-Down (Buck) Regulators Download 2.44 KB LTspice LT3685 Demo Circuit - 36V, 2A, 2.4MHz Step-Down Regulator (24V to 3.3V @ 2A) Download 3.00KB
Part Models 8
1ku List Price Starting From $3.66
modal bookmark icon

{{modalTitle}}

modal close icon

{{modalDescription}}

{{dropdownTitle}}

input down arrow
  • {{defaultSelectedText}}
    • {{#each projectNames}}
  • {{name}}
    • {{/each}} {{#if newProjectText}}
  • plus icon {{newProjectText}}
    • {{/if}}
{{#if toggleButtonDescription}}
{{toggleButtonDescription}}
{{/if}} {{#if newProjectTitle}}

{{newProjectTitle}}

{{projectNameErrorText}}

{{/if}}

LT3685

Documentation

6
overlayclose

Filters

1 Applied

mobileoverlaydownarrow
  • All
    TickIcon
  • Data Sheet
  • User Guide
  • Application Note
  • Reliability Data
  • All
    TickIcon
  • English
  • Japanese
resetfilter

Reset Filters

Data Sheet

2

PDF Vector

PDF

UPDATED 12/02/2008
English

LT3685: 36V, 2A, 2.4MHz Step-Down Switching Regulator Data Sheet (Rev.C)

Open PDF File

redirect
925.79 K
download

Download PDF

PDF Vector

PDF

UPDATED 03/13/2009
Japanese

LT3685: 36V、2A、2.4MHz降圧スイッチング・レギュレータ データシート

Open PDF File

redirect
2.00M
download

Download PDF

User Guide

2

PDF Vector

PDF

UPDATED 09/24/2009
English
DC1212A - Demo Manual redirect icon

289.00K

download

Download PDF

PDF Vector

PDF

UPDATED 09/24/2009
English
DC1167A - Demo Manual redirect icon

264.00K

download

Download PDF

Application Note

1

PDF Vector

PDF

UPDATED 12/04/2012
English
AN126 - 2-Wire Virtual Remote Sensing for Voltage Regulators - Clairvoyance Marries Remote Sensing redirect icon

1.00M

download

Download PDF

Reliability Data

1

PDF Vector

PDF

UPDATED 03/26/2018
English
R530 Reliability Data redirect icon

20.92 K

download

Download PDF

There are no results matching this criteria. Try resetting your filters or searching for a different term

close icon

Documentation

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. View our quality and reliability program and certifications for more information.

Part Model Pin/Package Drawing Documentation CAD Symbols, Footprints, and 3D Models
LT3685EDD#PBF 10-Lead DFN (3mm x 3mm w/ EP) external-link
  • HTML
  • Material Declaration external-link
  • HTML
  • Reliablity Data external-link
LT3685EDD#TRPBF 10-Lead DFN (3mm x 3mm w/ EP) external-link
  • HTML
  • Material Declaration external-link
  • HTML
  • Reliablity Data external-link
LT3685EMSE#PBF 10-Lead MSOP w/ EP external-link
  • HTML
  • Material Declaration external-link
  • HTML
  • Reliablity Data external-link
LT3685EMSE#TRPBF 10-Lead MSOP w/ EP external-link
  • HTML
  • Material Declaration external-link
  • HTML
  • Reliablity Data external-link
LT3685IDD#PBF 10-Lead DFN (3mm x 3mm w/ EP) external-link
  • HTML
  • Material Declaration external-link
  • HTML
  • Reliablity Data external-link
LT3685IDD#TRPBF 10-Lead DFN (3mm x 3mm w/ EP) external-link
  • HTML
  • Material Declaration external-link
  • HTML
  • Reliablity Data external-link
LT3685IMSE#PBF 10-Lead MSOP w/ EP external-link
  • HTML
  • Material Declaration external-link
  • HTML
  • Reliablity Data external-link
LT3685IMSE#TRPBF 10-Lead MSOP w/ EP external-link
  • HTML
  • Material Declaration external-link
  • HTML
  • Reliablity Data external-link

Filter by Model

reset

Reset Filters

Part Models

Product Lifecycle

PCN

Oct 11, 2022

- 22_0244

Epoxy Change from Henkel 8290 to 8290A for MSOP Package

LT3685EMSE#PBF

PRODUCTION

LT3685EMSE#TRPBF

PRODUCTION

LT3685IMSE#PBF

PRODUCTION

LT3685IMSE#TRPBF

PRODUCTION

pdf

PCN22_0244_Form

external-icon

xls

Material_Report

Download

pdf

Qualification Results Summary

external-icon

xlsm

Delta Qualification Matrix

Download

Jul 12, 2022

- 22_0157

UTAC Thai Limited (UTL) as Alternate Assembly Site for MSOP Packages [With Modification in BOM]

LT3685EMSE#PBF

PRODUCTION

LT3685EMSE#TRPBF

PRODUCTION

LT3685IMSE#PBF

PRODUCTION

LT3685IMSE#TRPBF

PRODUCTION

pdf

PCN22_0157_Form

external-icon

xls

Material_Report

Download

pdf

Qualification Results Summary

external-icon

xlsm

Delta Qualification Matrix

Download

Detailed Parts List

Jun 21, 2022

- 22_0050

UTAC Thai Limited (UTL) as Alternate Assembly Site for MSOP Packages / Devices

LT3685EMSE#PBF

PRODUCTION

LT3685EMSE#TRPBF

PRODUCTION

LT3685IMSE#PBF

PRODUCTION

LT3685IMSE#TRPBF

PRODUCTION

pdf

PCN22_0050_Form

external-icon

xls

Material_Report

Download

pdf

Qualification Results Summary

external-icon

xlsm

Delta Qualification Matrix

Download

Feb 4, 2020

- 20_0130

Laser Top Mark Conversion for 10-Lead MSOP Packages Assembled in ADPG and UTAC

LT3685EMSE#PBF

PRODUCTION

LT3685EMSE#TRPBF

PRODUCTION

LT3685IMSE#PBF

PRODUCTION

LT3685IMSE#TRPBF

PRODUCTION

pdf

PCN20_0130_Form

external-icon

xls

Material_Report

Download

Filter by Model

reset

Reset Filters

Part Models

Product Lifecycle

PCN

Oct 11, 2022

- 22_0244

arrow down

Epoxy Change from Henkel 8290 to 8290A for MSOP Package

LT3685EMSE#PBF

PRODUCTION

LT3685EMSE#TRPBF

PRODUCTION

LT3685IMSE#PBF

PRODUCTION

LT3685IMSE#TRPBF

PRODUCTION

pdf

PCN22_0244_Form

external-icon

xls

Material_Report

Download

pdf

Qualification Results Summary

external-icon

xlsm

Delta Qualification Matrix

Download
Jul 12, 2022

- 22_0157

arrow down

UTAC Thai Limited (UTL) as Alternate Assembly Site for MSOP Packages [With Modification in BOM]

LT3685EMSE#PBF

PRODUCTION

LT3685EMSE#TRPBF

PRODUCTION

LT3685IMSE#PBF

PRODUCTION

LT3685IMSE#TRPBF

PRODUCTION

pdf

PCN22_0157_Form

external-icon

xls

Material_Report

Download

pdf

Qualification Results Summary

external-icon

xlsm

Delta Qualification Matrix

Download
Detailed Parts List
Jun 21, 2022

- 22_0050

arrow down

UTAC Thai Limited (UTL) as Alternate Assembly Site for MSOP Packages / Devices

LT3685EMSE#PBF

PRODUCTION

LT3685EMSE#TRPBF

PRODUCTION

LT3685IMSE#PBF

PRODUCTION

LT3685IMSE#TRPBF

PRODUCTION

pdf

PCN22_0050_Form

external-icon

xls

Material_Report

Download

pdf

Qualification Results Summary

external-icon

xlsm

Delta Qualification Matrix

Download
Feb 4, 2020

- 20_0130

arrow down

Laser Top Mark Conversion for 10-Lead MSOP Packages Assembled in ADPG and UTAC

LT3685EMSE#PBF

PRODUCTION

LT3685EMSE#TRPBF

PRODUCTION

LT3685IMSE#PBF

PRODUCTION

LT3685IMSE#TRPBF

PRODUCTION

pdf

PCN20_0130_Form

external-icon

xls

Material_Report

Download

Software & Part Ecosystem

Parts Product Life Cycle Description

Digital Power System Managers1
LTC2974
popup image
Cart

RECOMMENDED FOR NEW DESIGNS

4-Channel PMBus Power System Manager Featuring Accurate Output Current Measurement

Dual-Supply Monitors1
LTC2960
popup image
Cart

RECOMMENDED FOR NEW DESIGNS

36V Nano-Current Two-Input Voltage Monitor

Silicon Oscillators1
LTC6902
popup image
Cart

PRODUCTION

Multiphase Oscillator with Spread Spectrum Frequency Modulation

Surge Stopper, Overvoltage, and Overcurrent Protection1
LT4363
popup image
Cart

RECOMMENDED FOR NEW DESIGNS

High Voltage Surge Stopper with Current Limit

Evaluation Kits 2

reference details image

DC1167A

LT3685EMSE Demo Board | (MSOP) 6.3V ≤ VIN ≤ 38V (60V Transients), VOUT = 5V @ 2A

zoom

DC1167A

LT3685EMSE Demo Board | (MSOP) 6.3V ≤ VIN ≤ 38V (60V Transients), VOUT = 5V @ 2A

download icon

Download

 print icon

Print
DC1167A
LT3685EMSE Demo Board | (MSOP) 6.3V ≤ VIN ≤ 38V (60V Transients), VOUT = 5V @ 2A
Buy Now View Details

Product Detail

Demonstration circuit 1167 is a monolithic step-down DC/DC switching regulator featuring the LT3685 in the MSOP-10 exposed pad package. The demo board provides 5V @ 2A from a 6.3V to 38V input and has transient protection up to 60V. The demo boards default switching frequency is 500kHz, but the LT3685 has a SYNC pin which allows frequency synchronization to an external clock over a 250kHz to 2MHz range.

Resources

pdf icon

PDF

DC1167A - Schematic Download

24.00K

pdf icon

ZIP

DC1167A - Design File Download

966.00K

pdf icon

PDF

DC1167A - Demo Manual Download

264.00K

Show More Arrow image
reference details image

DC1212A-B

LT3685EDD Demo Board | (DFN) EN55022-Compliant, 6.3V ≤ VIN ≤ 38V (60V Transients), VOUT = 5V @ 2A

zoom

DC1212A-B

LT3685EDD Demo Board | (DFN) EN55022-Compliant, 6.3V ≤ VIN ≤ 38V (60V Transients), VOUT = 5V @ 2A

download icon

Download

 print icon

Print
DC1212A-B
LT3685EDD Demo Board | (DFN) EN55022-Compliant, 6.3V ≤ VIN ≤ 38V (60V Transients), VOUT = 5V @ 2A
Buy Now View Details

Product Detail

Demonstration circuit 1212A-B is a monolithic step-dwon DC/DC switching regulatro featuring the LT3685 in the 3x3 DFN-10 package. The demo board provides 5V@2A from a 6.3V to 38V input and has transient protection up to 60V. The demo boards default switching frequency is 800kHz, but the LT3685 has a SYNC pin which allows frequency synchronization to an external clock over a 250kHz to 2MHz range. The LT3685's quiescent current is 0.9mA, while the LT3480 has a 70uA quiescent current.


An EMC filter at the input makes the circuit compatible with EMC standard EN55022 Class B.



Resources

pdf icon

PDF

DC1212A - Schematic Download

22.00K

pdf icon

PDF

DC1212A - Demo Manual Download

289.00K

pdf icon

ZIP

DC1212A - Design File Download

684.00K

Show More Arrow image

Evaluation Kits2

evaluation kit item images

DC1167A

LT3685EMSE Demo Board | (MSOP) 6.3V ≤ VIN ≤ 38V (60V Transients), VOUT = 5V @ 2A
evaluation kit item images

DC1212A-B

LT3685EDD Demo Board | (DFN) EN55022-Compliant, 6.3V ≤ VIN ≤ 38V (60V Transients), VOUT = 5V @ 2A

Tools & Simulations 1

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.

spice tool Lt Spice

LT3685 - Step-Down (Buck) Regulators Download

2.44 K

spice tool Lt Spice

LT3685 Demo Circuit - 36V, 2A, 2.4MHz Step-Down Regulator (24V to 3.3V @ 2A) Download

3.00K

Recently Viewed

Part Details
Documentation
Software & Part Ecosystem
Evaluation Kit
Tools & Simulations
Latest Discussions