Products
LTC3851
PRODUCTIONSynchronous Step-Down Switching Regulator Controller
- Part Models
- 12
- 1ku List Price
- Starting From $2.40
Viewing:
Overview
- Wide VIN Range: 4V to 38V Operation
- RSENSE or DCR Current Sensing
- ±1% Output Voltage Accuracy
- Phase-Lockable Fixed Frequency: 250kHz to 750kHz
- Dual N-Channel MOSFET Synchronous Drive
- Very Low Dropout Operation: 99% Duty Cycle
- Adjustable Output Voltage Soft-Start or Tracking
- Output Current Foldback Limiting
- Output Overvoltage Protection
- 5V Internal Regulator
- OPTI-LOOP® Compensation Minimizes COUT
- Selectable Continuous, Pulse-Skipping or Burst Mode® Operation at Light Loads
- Low Shutdown IQ: 20μA
- VOUT Range: 0.8V to 5.5V
- Thermally Enhanced 16-Lead MSOP, 16-Lead Narrow SSOP or 3mm × 3mm QFN Package
The LTC3851 is a high performance synchronous step-down switching regulator controller that drives an all N-channel synchronous power MOSFET stage. A constant frequency current mode architecture allows a phase-lockable frequency of up to 750kHz.
OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3851 features a precision 0.8V reference that is compatible with a wide 4V to 38V input supply range.
The TK/SS pin ramps the output voltage during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The MODE/PLLIN pin selects among Burst Mode operation, pulse skipping mode or continuous inductor current mode at light loads and allows the IC to be synchronized to an external clock.
The LTC3851-1 is a version with a power good output signal instead of adjustable current limit.
| Features | |
| LTC3851 | Not Recommended For New Designs |
| LTC3851-1 | Not Recommended For New Designs |
| LTC3851A | Adjustable Current Limit |
| LTC3851A-1 | PGOOD Output |
Applications
- Automotive Systems
- Telecom Systems
- Industrial Equipment
- Distributed DC Power Systems
Documentation
Data Sheet 1
User Guide 1
Application Note 1
Technical Articles 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 |
|---|---|---|---|
| LTC3851EGN#PBF | 16-Lead SSOP (Narrow 0.15 Inch) | ||
| LTC3851EGN#TRPBF | 16-Lead SSOP (Narrow 0.15 Inch) | ||
| LTC3851EMSE#PBF | 16-Lead MSOP w/ EP | ||
| LTC3851EMSE#TRPBF | 16-Lead MSOP w/ EP | ||
| LTC3851EUD#PBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | ||
| LTC3851EUD#TRPBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | ||
| LTC3851IGN#PBF | 16-Lead SSOP (Narrow 0.15 Inch) | ||
| LTC3851IGN#TRPBF | 16-Lead SSOP (Narrow 0.15 Inch) | ||
| LTC3851IMSE#PBF | 16-Lead MSOP w/ EP | ||
| LTC3851IMSE#TRPBF | 16-Lead MSOP w/ EP | ||
| LTC3851IUD#PBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | ||
| LTC3851IUD#TRPBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Oct 3, 2024 - 24_0235 (QSOP/SSOP PKG) Migrating Bottom Trace Code Marking to Top Side Laser Marking |
||
| LTC3851EGN#PBF | PRODUCTION | |
| LTC3851EGN#TRPBF | PRODUCTION | |
| LTC3851IGN#PBF | PRODUCTION | |
| LTC3851IGN#TRPBF | PRODUCTION | |
|
Oct 11, 2022 - 22_0235 Epoxy Change from Henkel 8290 to 8290A for GN Package |
||
| LTC3851EGN#PBF | PRODUCTION | |
| LTC3851EGN#TRPBF | PRODUCTION | |
| LTC3851IGN#PBF | PRODUCTION | |
| LTC3851IGN#TRPBF | PRODUCTION | |
|
Apr 6, 2022 - 22_0066 Laser Top Mark for 16QSOP Assembled in ADPG [PNG] |
||
| LTC3851EGN#PBF | PRODUCTION | |
| LTC3851EGN#TRPBF | PRODUCTION | |
| LTC3851IGN#PBF | PRODUCTION | |
| LTC3851IGN#TRPBF | PRODUCTION | |
|
Nov 8, 2021 - 20_0245 Notification of Wafer Fab Location Change for 0.6µm BICMOS Process Devices from ADI Milpitas (Hillview) to Vanguard Int. (Taiwan) |
||
| LTC3851EGN#PBF | PRODUCTION | |
| LTC3851EGN#TRPBF | PRODUCTION | |
| LTC3851EMSE#PBF | PRODUCTION | |
| LTC3851EMSE#TRPBF | PRODUCTION | |
| LTC3851EUD#PBF | PRODUCTION | |
| LTC3851EUD#TRPBF | PRODUCTION | |
| LTC3851IGN#PBF | PRODUCTION | |
| LTC3851IGN#TRPBF | PRODUCTION | |
| LTC3851IMSE#PBF | PRODUCTION | |
| LTC3851IMSE#TRPBF | PRODUCTION | |
| LTC3851IUD#PBF | PRODUCTION | |
| LTC3851IUD#TRPBF | PRODUCTION | |
|
Jun 5, 2024 - 24_0003 Epoxy Change from Henkel 8290 to 8290A for MSOP Package (2) |
||
| LTC3851EMSE#PBF | PRODUCTION | |
| LTC3851EMSE#TRPBF | PRODUCTION | |
|
Feb 4, 2020 - 20_0132 Laser Top Mark for 16-Lead MSOP Packages Assembled in ADPG and UTAC |
||
| LTC3851EMSE#PBF | PRODUCTION | |
| LTC3851EMSE#TRPBF | PRODUCTION | |
| LTC3851IMSE#PBF | PRODUCTION | |
| LTC3851IMSE#TRPBF | PRODUCTION | |
|
Oct 11, 2022 - 22_0244 Epoxy Change from Henkel 8290 to 8290A for MSOP Package |
||
| LTC3851IMSE#PBF | PRODUCTION | |
| LTC3851IMSE#TRPBF | PRODUCTION | |
|
Apr 18, 2022 - 22_0050 UTAC Thai Limited (UTL) as Alternate Assembly Site for MSOP Packages / Devices |
||
| LTC3851IMSE#PBF | PRODUCTION | |
| LTC3851IMSE#TRPBF | PRODUCTION | |
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
| Parts | Product Life Cycle | Description |
|---|---|---|
| Circuit Monitors 1 | ||
| LTC2960 | RECOMMENDED FOR NEW DESIGNS | 36V Nano-Current Two-Input Voltage Monitor |
| Oscillators 1 | ||
| LTC6909 | PRODUCTION | 1 to 8 Output, Multiphase Silicon Oscillator with Spread Spectrum Modulation |
| Power System Management (PSM) & Sequencers 1 | ||
| LTC2974 | RECOMMENDED FOR NEW DESIGNS | 4-Channel PMBus Power System Manager Featuring Accurate Output Current Measurement |
| Parts | Product Life Cycle | Description |
|---|---|---|
| LTC3851A | RECOMMENDED FOR NEW DESIGNS | Synchronous Step-Down Switching Regulator Controller |
Tools & Simulations
LTspice
Models for the following parts are available in LTspice:
- LTC3851
- LTC3851-1
- LTC3851A
- LTC3851A-1
LTpowerCAD
Design tools for the following parts are available in LTpowerCAD:
- LTC3851A
- LTC3851A-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.
