LT3685
PRODUCTION36V, 2A, 2.4MHz Step-Down Switching Regulator
- Part Models
- 8
- 1ku List Price
- Starting From $4.64
Overview
- 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
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
Documentation
Data Sheet 1
User Guide 2
Application Note 1
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) | ||
| LT3685EDD#TRPBF | 10-Lead DFN (3mm x 3mm w/ EP) | ||
| LT3685EMSE#PBF | 10-Lead MSOP w/ EP | ||
| LT3685EMSE#TRPBF | 10-Lead MSOP w/ EP | ||
| LT3685IDD#PBF | 10-Lead DFN (3mm x 3mm w/ EP) | ||
| LT3685IDD#TRPBF | 10-Lead DFN (3mm x 3mm w/ EP) | ||
| LT3685IMSE#PBF | 10-Lead MSOP w/ EP | ||
| LT3685IMSE#TRPBF | 10-Lead MSOP w/ EP |
| 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 | |
|
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 | |
|
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 | |
|
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 | |
|
Apr 17, 2025 - 25_0043 Change of Gold to Copper Wire and BOM (Automotive) |
||
| LT3685IDD#TRPBF | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
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Request a Driver/SoftwareHardware Ecosystem
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Tools & Simulations
LTspice 1
Models for the following parts are available in LTspice:
- LT3685
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.
Evaluation Kits
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