LT8611
RECOMMENDED FOR NEW DESIGNS42V, 2.5A Synchronous Step-Down Regulator with Current Sense and 2.5μA Quiescent Current
- Part Models
- 8
- 1ku List Price
- Starting From $5.76
Overview
- Rail-to-Rail Current Sense Amplifier with Monitor
- Wide Input Voltage Range: 3.4V to 42V
- Ultralow Quiescent Current Burst Mode® Operation:
- 2.5μA IQ Regulating 12VIN to 3.3VOUT
- Output Ripple < 10mVP-P
- High Efficiency Synchronous Operation:
- 96% Efficiency at 1A, 5VOUT from 12VIN
- 94% Efficiency at 1A, 3.3VOUT from 12VIN
- Fast Minimum Switch-On Time: 50ns
- Low Dropout Under All Conditions: 200mV at 1A
- Allows Use Of Small Inductors
- Low EMI
- Adjustable and Synchronizable: 200kHz to 2.2MHz
- Current Mode Operation
- Accurate 1V Enable Pin Threshold
- Internal Compensation
- Output Soft-Start and Tracking
- Small Thermally Enhanced 3mm × 5mm 24-Lead QFN Package
- AEC-Q100 Qualified for Automotive Applications
The LT8611 is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that consumes only 2.5μA of quiescent current. Top and bottom power switches are included with all necessary circuitry to minimize the need for external components. The built-in current sense amplifier with monitor and control pins allows accurate input or output current regulation and limiting. Low ripple Burst Mode operation enables high efficiency down to very low output currents while keeping the output ripple below 10mVP-P. A SYNC pin allows synchronization to an external clock. Internal compensation with peak current mode topology allows the use of small inductors and results in fast transient response and good loop stability. The EN/UV pin has an accurate 1V threshold and can be used to program VIN undervoltage lockout or to shut down the LT8611 reducing the input supply current to 1μA. A capacitor on the TR/SS pin programs the output voltage ramp rate during start-up. The PG flag signals when VOUT is within ±9% of the programmed output voltage as well as fault conditions. The LT8611 is available in a small 24-lead 3mm × 5mm QFN package with exposed pad for low thermal resistance.
Applications
- Automotive and Industrial Supplies
- General Purpose Step-Down
- CCCV Power Supplies
Documentation
Data Sheet 1
User Guide 1
Application Note 1
Design Note 1
Technical Articles 3
Brochure 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 |
|---|---|---|---|
| LT8611EUDD#PBF | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | ||
| LT8611EUDD#TRPBF | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | ||
| LT8611EUDD#WPBF | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | ||
| LT8611EUDD#WTRPBF | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | ||
| LT8611IUDD#PBF | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | ||
| LT8611IUDD#TRPBF | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | ||
| LT8611IUDD#WPBF | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | ||
| LT8611IUDD#WTRPBF | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Feb 14, 2025 - 25_0017 Bond Wire Change from Gold to Copper |
||
| LT8611EUDD#PBF | PRODUCTION | |
|
Sep 30, 2020 - 20_0293 Test Site Transfer from Analog Devices Singapore to UTAC Thailand |
||
| LT8611EUDD#PBF | PRODUCTION | |
| LT8611EUDD#TRPBF | PRODUCTION | |
| LT8611IUDD#PBF | PRODUCTION | |
| LT8611IUDD#TRPBF | PRODUCTION | |
|
Apr 11, 2019 - 19_0067 Notification of Wafer Fab Location Change for 0.35 BCD Process |
||
| LT8611EUDD#PBF | PRODUCTION | |
| LT8611EUDD#TRPBF | PRODUCTION | |
| LT8611IUDD#PBF | PRODUCTION | |
| LT8611IUDD#TRPBF | PRODUCTION | |
|
Apr 14, 2025 - 25_0017 Bond Wire Change from Gold to Copper |
||
| LT8611EUDD#TRPBF | PRODUCTION | |
| LT8611EUDD#WPBF | PRODUCTION | |
| LT8611EUDD#WTRPBF | PRODUCTION | |
| LT8611IUDD#WPBF | PRODUCTION | |
| LT8611IUDD#WTRPBF | PRODUCTION | |
|
Apr 17, 2025 - 25_0043 Change of Gold to Copper Wire and BOM (Automotive) |
||
| LT8611EUDD#WPBF | PRODUCTION | |
| LT8611EUDD#WTRPBF | 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 |
| Hot Swap Controllers 1 | ||
| LTC4364 | RECOMMENDED FOR NEW DESIGNS | Surge Stopper with Ideal Diode |
| Ideal Diodes and PowerPath Controllers 1 | ||
| LTC4370 | RECOMMENDED FOR NEW DESIGNS | Two-Supply Diode-OR Current Balancing Controller |
| Power System Management (PSM) & Sequencers 1 | ||
| LTC2974 | RECOMMENDED FOR NEW DESIGNS | 4-Channel PMBus Power System Manager Featuring Accurate Output Current Measurement |
Tools & Simulations
LTspice 4
- LT8611/LTC4412 Demo Circuit - Solar Powered Battery Charger with µP Controlled MPPT (4.2-42V to 4.1V @ 1A)
- LT8611 Demo Circuit - Negative Converter with 1A Output Current Limit (3.8-42V to -3.3V @ 1A)
- LT8611 Demo Circuit - µPower Synchronous Step-Down Regulator with Current Sense (3.8-42V to 3.3V @ 2.5A)
- LT8611 Demo Circuit - CCCV Li-Ion Battery Charger (3.8-42V to 4.1V @ 1A)
Models for the following parts are available in LTspice:
- LT8611
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
LT8611 Demo Board | Micropower Sync Buck with Current Sense, 3.8V ≤ VIN ≤ 42V, VOUT = 3.3V @ 2.5A