LT8611
42V, 2.5A Synchronous Step-Down Regulator with Current Sense and 2.5μA Quiescent Current
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Overview
Features and Benefits
- 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
Product Details
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
Product Categories
Markets and Technologies
Product Lifecycle
Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Documentation & Resources
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R570 Reliability Data3/23/2018PDF415 K
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DC1750A - Demo Manual6/14/2012PDF268K
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42V, 2MHz Sync Buck6/26/2012PDF522K
Tools & Simulations
LTspice
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Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
LTspice Simulations
Models for the following parts are available in LTspice:
LT8611
Design Resources
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 Number | Material Declaration | Reliability Data | Pin/Package Drawing | CAD Symbols, Footprints & 3D Models |
|---|---|---|---|---|
| LT8611EUDD#PBF | Material Declaration | Reliability Data | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | |
| LT8611EUDD#TRPBF | Material Declaration | Reliability Data | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | |
| LT8611EUDD#WPBF | Material Declaration | Reliability Data | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | |
| LT8611EUDD#WTRPBF | Material Declaration | Reliability Data | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | |
| LT8611IUDD#PBF | Material Declaration | Reliability Data | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | |
| LT8611IUDD#TRPBF | Material Declaration | Reliability Data | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | |
| LT8611IUDD#WPBF | Material Declaration | Reliability Data | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | |
| LT8611IUDD#WTRPBF | Material Declaration | Reliability Data | 24-Lead QFN (3mm x 5mm x 0.75mm w/ EP) | |
| Wafer Fabrication Data | R570 Reliability Data |
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LT8611 Discussions
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Evaluation Boards
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.