LTC3649
RECOMMENDED FOR NEW DESIGNS60V, 4A Synchronous Step-Down Regulator with Rail-to-Rail Programmable Output
- Part Models
- 8
- 1ku List Price
- Starting From $8.51
Overview
- Wide VIN Range: 3.1V to 60V
- Wide VOUT Range: 0V to (VIN – 0.5V)
- Single Resistor VOUT Programming
- Integrated 110mΩ Top N-Channel/50mΩ Bottom N-Channel MOSFETs
- 95% Efficiency with 12VIN and 5VOUT
- Regulated IQ: 440μA, Shutdown IQ: 18μA
- Accurate Current Monitoring (±4%) without Sense Resistor
- Accurate Resistor Programmable Frequency (300kHz to 3MHz) with ±50% Frequency Sync Range
- Accurate Programmable Output Current
- Input Voltage Regulation for MPPT Applications
- ±0.8% Output Voltage Accuracy
- Peak Current Mode Operation
- Programmable Wire Drop Compensation
- Burst Mode® Operation, Forced Continuous Mode
- Internal Compensation and Programmable Soft-Start
- Overtemperature Protection
- Available in Thermally Enhanced 28-Lead (4mm × 5mm) QFN and TSSOP Packages
The LTC3649 is a high efficiency 60V, 4A synchronous monolithic step-down regulator. The regulator features a single resistor programmable output voltage, internal compensation and high efficiencies over a wide VOUT range.
The step-down regulator operates from an input voltage range of 3.1V to 60V and provides an adjustable rail-to-rail output range from (VIN – 0.5V) to ground while delivering up to 4A of output current. The switching frequency is also adjusted with an external resistor. A user-selectable mode input is provided to allow the user to trade off ripple noise for efficiency at light loads; Burst Mode operation provides the highest efficiency at light loads, while forced continuous mode provides low output ripple. The MODE/SYNC pin can also be used to allow the user to synchronize the switching frequency to an external clock.
The LTC3649 operates with a peak current mode architecture that allows for fast transient response with inherent cycle-to-cycle current limit protection. It also features programmable output current limit, current monitoring and input voltage regulation.
Applications
- Industrial Applications
- Automotive Applications
Documentation
Data Sheet 1
User Guide 2
Design Note 3
Technical Articles 3
Video 2
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 |
|---|---|---|---|
| LTC3649EFE#PBF | 28-Lead TSSOP w/ EP | ||
| LTC3649EFE#TRPBF | 28-Lead TSSOP w/ EP | ||
| LTC3649EUFD#PBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LTC3649EUFD#TRPBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LTC3649IFE#PBF | 28-Lead TSSOP w/ EP | ||
| LTC3649IFE#TRPBF | 28-Lead TSSOP w/ EP | ||
| LTC3649IUFD#PBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LTC3649IUFD#TRPBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Feb 14, 2025 - 25_0016 Bond Wire Change from Gold to Copper Wire (Notification Only) |
||
| LTC3649EFE#PBF | PRODUCTION | |
| LTC3649EFE#TRPBF | PRODUCTION | |
|
Apr 6, 2022 - 22_0068 Laser Top Mark for ETSSOP and TSSOP Packages Assembled in ADPG [PNG] and UTL |
||
| LTC3649EFE#PBF | PRODUCTION | |
| LTC3649EFE#TRPBF | PRODUCTION | |
| LTC3649IFE#PBF | PRODUCTION | |
| LTC3649IFE#TRPBF | PRODUCTION | |
|
May 17, 2019 - 19_0067 Notification of Wafer Fab Location Change for 0.35 BCD Process |
||
| LTC3649EFE#PBF | PRODUCTION | |
| LTC3649EFE#TRPBF | PRODUCTION | |
| LTC3649EUFD#PBF | PRODUCTION | |
| LTC3649EUFD#TRPBF | PRODUCTION | |
| LTC3649IFE#PBF | PRODUCTION | |
| LTC3649IFE#TRPBF | PRODUCTION | |
| LTC3649IUFD#PBF | PRODUCTION | |
| LTC3649IUFD#TRPBF | PRODUCTION | |
|
Apr 9, 2025 - 25_0016 Bond Wire Change from Gold to Copper Wire (Notification Only) |
||
| LTC3649EUFD#PBF | PRODUCTION | |
| LTC3649EUFD#TRPBF | PRODUCTION | |
| LTC3649IFE#PBF | PRODUCTION | |
| LTC3649IFE#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 |
|---|---|---|
| Hot Swap Controllers 1 | ||
| LT4363 | RECOMMENDED FOR NEW DESIGNS | High Voltage Surge Stopper with Current Limit |
Tools & Simulations
LTspice 5
- LTC3649 Demo Circuit - High Voltage Monolithic Synchronous Buck Regulator with Output Voltage Control (10-60V to 2.5-7.5V @ 4A)
- LTC3649 Demo Circuit - High Voltage Monolothic Synchronous Buck Regulator (4-60V to 5V @ 4A)
- LTC3649 Demo Circuit - High Voltage Monolothic Synchronous Buck Regulator with Cable Drop Compensation (4-60V to 5V @ 4A)
- LTC3649 Demo Circuit - Hold-Up Circuit Using a Buck Regulator with Vin Boost Capabilities (5.5-60V to 5V @ 4A, 8V Hold-Up)
- LTC3649 Demo Circuit - High Voltage Synchronous Buck Regulator with Output Voltage Control (10-60V to 5V @ 4A)
Models for the following parts are available in LTspice:
- LTC3649
LTpowerCAD 1
Design tools for the following parts are available in LTpowerCAD:
- LTC3649
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.
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
