LT3845
NOT RECOMMENDED FOR NEW DESIGNSHigh Voltage Synchronous Current Mode Step-Down Controller with Adjustable Operating Frequency
- Part Models
- 8
- 1ku List Price
- Starting From $5.31
Overview
- High Voltage Operation: Up to 60V
- Synchronizable Up to 600kHz
- Adjustable Constant Frequency: 100kHz to 500kHz
- Output Voltages Up to 36V
- Adaptive Nonoverlap Circuitry Prevents Switch Shoot-Through
- Reverse Inductor Current Inhibit for Discontinuous Operation Improves Efficiency with Light Loads
- Programmable Soft-Start
- 120μA No Load Quiescent Current
- 10μA Shutdown Supply Current
- 1% Regulation Accuracy
- Standard Gate N-Channel Power MOSFETs
- Current Limit Unaffected by Duty Cycle
- Reverse Overcurrent Protection
- 16-Lead Thermally Enhanced TSSOP Package, 16-Pin PDIP
The LT3845 is a high voltage, synchronous, current mode controller used for medium to high power, high efficiency supplies. It offers a wide 4V to 60V input range (7.5V minimum start-up voltage). An on-board regulator simplifies the biasing requirements by providing IC power directly from VIN.
Burst Mode® operation maintains high efficiency at light loads by reducing IC quiescent current to 120μA. Light load efficiency is also improved with the reverse inductor current inhibit function which supports discontinuous operation.
Additional features include adjustable fixed operating frequency that can be synchronized to an external clock for noise sensitive applications, gate drivers capable of driving large N-channel MOSFETs, a precision undervoltage lockout, 10μA shutdown current, short-circuit protection and a programmable soft-start.
The LT3845 is available in a 16-lead thermally enhanced TSSOP package and 16-pin through hole N package.
| Features | |
| LT3845 | - |
| LT3845A | Improved Performance In Over Current Conditions |
Applications
- 12V and 42V Automotive and Heavy Equipment
- 48V Telecom Power Supplies
- Avionics and Industrial Control Systems
- Distributed Power Converters
Documentation
Data Sheet 1
User Guide 1
Design Note 1
Controlled Drawings 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 |
|---|---|---|---|
| LT3845EFE#PBF | 16-Lead TSSOP w/ EP | ||
| LT3845EFE#TRPBF | 16-Lead TSSOP w/ EP | ||
| LT3845EN#PBF | 16-Lead PDIP (Narrow 0.30 Inch) | ||
| LT3845IFE#PBF | 16-Lead TSSOP w/ EP | ||
| LT3845IFE#TRPBF | 16-Lead TSSOP w/ EP | ||
| LT3845MPFE | 16-Lead TSSOP w/ EP | ||
| LT3845MPFE#PBF | 16-Lead TSSOP w/ EP | ||
| LT3845MPFE#TRPBF | 16-Lead TSSOP w/ EP |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Apr 6, 2022 - 22_0068 Laser Top Mark for ETSSOP and TSSOP Packages Assembled in ADPG [PNG] and UTL |
||
| LT3845EFE#PBF | PRODUCTION | |
| LT3845EFE#TRPBF | PRODUCTION | |
| LT3845IFE#PBF | PRODUCTION | |
| LT3845IFE#TRPBF | PRODUCTION | |
| LT3845MPFE | ||
| LT3845MPFE#PBF | PRODUCTION | |
| LT3845MPFE#TRPBF | PRODUCTION | |
|
Oct 11, 2022 - 22_0241 Epoxy Change from Henkel 8290 to 8290A for PDIP Package |
||
| LT3845EN#PBF | PRODUCTION | |
|
Aug 6, 2022 - 22_0172 Laser Top Mark Conversion for PDIP Packages Assembled in ADPG [PNG] |
||
| LT3845EN#PBF | PRODUCTION | |
|
May 29, 2025 - 25_0024 Carsem SnPb Packaging End of Life |
||
| LT3845MPFE | ||
This is the most up-to-date revision of the Data Sheet.
Software Resources
Can't find the software or driver you need?
Request a Driver/SoftwareHardware Ecosystem
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| Circuit Monitors 1 | ||
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| Hot Swap Controllers 1 | ||
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| Oscillators 1 | ||
| LTC6909 | PRODUCTION | 1 to 8 Output, Multiphase Silicon Oscillator with Spread Spectrum Modulation |
| Switching Regulators & Controllers 1 | ||
| LTC3880 | RECOMMENDED FOR NEW DESIGNS | Dual Output PolyPhase Step-Down DC/DC Controller with Digital Power System Management |
| Parts | Product Life Cycle | Description |
|---|---|---|
| LT3845A | RECOMMENDED FOR NEW DESIGNS | High Voltage Synchronous Current Mode Step-Down Controller with Adjustable Operating Frequency |
Tools & Simulations
LTspice 1
Models for the following parts are available in LTspice:
- LT3845
- LT3845A
LTpowerCAD
Design tools for the following parts are available in LTpowerCAD:
- LT3845
- LT3845A
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.
