LT3973
PRODUCTION42V, 750mA Step-Down Regulator with 2.5μA Quiescent Current and Integrated Diodes
- Part Models
- 36
- 1ku List Price
- Starting From $4.20
Overview
- Ultralow Quiescent Current
2.5μA IQ at 12VIN to 3.3VOUT - Low Ripple Burst Mode® Operation
Output Ripple < 10mVP-P - Wide Input Voltage Range: 4.2V to 42V Operating
- Adjustable Switching Frequency: 200kHz to 2.2MHz
- Integrated Boost and Catch Diodes
- 750mA Output Current
- Excellent Start-Up and Dropout Performance
- Fixed Output Voltages: 3.3V, 5V
- 1.9μA IQ at 12VIN
- Accurate Programmable Undervoltage Lockout
- Low Shutdown Current: IQ = 0.75μA
- Internal Catch Diode Current Limit
- Power Good Flag
- Thermal Shutdown
- Small, Thermally Enhanced 10-Lead MSOP and (3mm × 3mm) DFN Packages
The LT3973 is an adjustable frequency monolithic buck switching regulator that accepts a wide input voltage range up to 42V, and consumes only 2.5μA of quiescent current. A high efficiency switch is included on the die along with the catch diode, boost diode, and the necessary oscillator, control and logic circuitry. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping the output ripple below 10mV in a typical application. A minimum dropout voltage of 530mV is maintained when the input voltage drops below the programmed output voltage, such as during automotive cold crank. Current mode topology is used for fast transient response and good loop stability. A catch diode current limit provides protection against shorted outputs and overvoltage conditions, with thermal shutdown providing additional fault protection. An accurate programmable undervoltage lockout feature is available, producing a low shutdown current of 0.75μA. A power good flag signals when VOUT reaches 90% of the programmed output voltage. The LT3973 is available in small, thermally enhanced 10-lead MSOP and 3mm × 3mm DFN packages.
Applications
- Automotive Battery Regulation
- Power for Portable Products
- Industrial Supplies
- Gate Drive Bias
Documentation
Data Sheet 1
User Guide 1
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 Models | Product Lifecycle | PCN |
|---|---|---|
|
Apr 17, 2025 - 25_0043 Change of Gold to Copper Wire and BOM (Automotive) |
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| LT3973EDD#PBF | PRODUCTION | |
| LT3973EDD#TRPBF | PRODUCTION | |
| LT3973EDD-3.3#PBF | PRODUCTION | |
| LT3973EDD-3.3#TRPBF | PRODUCTION | |
| LT3973EDD-5#PBF | PRODUCTION | |
| LT3973EDD-5#TRPBF | PRODUCTION | |
| LT3973HDD#PBF | PRODUCTION | |
| LT3973HDD#TRPBF | PRODUCTION | |
| LT3973HDD-3.3#PBF | PRODUCTION | |
| LT3973HDD-3.3#TRPBF | PRODUCTION | |
| LT3973HDD-5#PBF | PRODUCTION | |
| LT3973HDD-5#TRPBF | PRODUCTION | |
| LT3973IDD-3.3#PBF | PRODUCTION | |
| LT3973IDD-3.3#TRPBF | PRODUCTION | |
| LT3973IDD-5#PBF | PRODUCTION | |
| LT3973IDD-5#TRPBF | PRODUCTION | |
|
Apr 17, 2025 - 25_0119 Bond Wire Change from Gold to Copper (Automotive) |
||
| LT3973EMSE#PBF | PRODUCTION | |
| LT3973EMSE#TRPBF | PRODUCTION | |
| LT3973EMSE-3.3#PBF | PRODUCTION | |
| LT3973EMSE-3.3#TRPBF | PRODUCTION | |
| LT3973EMSE-5#PBF | PRODUCTION | |
| LT3973EMSE-5#TRPBF | PRODUCTION | |
| LT3973HMSE#PBF | PRODUCTION | |
| LT3973HMSE#TRPBF | PRODUCTION | |
| LT3973HMSE-3.3#PBF | PRODUCTION | |
| LT3973HMSE-3.3#TRPBF | PRODUCTION | |
| LT3973HMSE-5#PBF | PRODUCTION | |
| LT3973HMSE-5#TRPBF | PRODUCTION | |
| LT3973IMSE-3.3#PBF | PRODUCTION | |
| LT3973IMSE-3.3#TRPBF | PRODUCTION | |
| LT3973IMSE-5#PBF | PRODUCTION | |
| LT3973IMSE-5#TRPBF | PRODUCTION | |
|
Jun 5, 2024 - 24_0003 Epoxy Change from Henkel 8290 to 8290A for MSOP Package (2) |
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| LT3973EMSE#PBF | PRODUCTION | |
| LT3973EMSE#TRPBF | PRODUCTION | |
| LT3973EMSE-3.3#PBF | PRODUCTION | |
| LT3973EMSE-3.3#TRPBF | PRODUCTION | |
| LT3973EMSE-5#PBF | PRODUCTION | |
| LT3973EMSE-5#TRPBF | PRODUCTION | |
| LT3973HMSE#PBF | PRODUCTION | |
| LT3973HMSE#TRPBF | PRODUCTION | |
| LT3973HMSE-3.3#PBF | PRODUCTION | |
| LT3973HMSE-3.3#TRPBF | PRODUCTION | |
| LT3973HMSE-5#PBF | PRODUCTION | |
| LT3973HMSE-5#TRPBF | PRODUCTION | |
| LT3973IMSE-3.3#PBF | PRODUCTION | |
| LT3973IMSE-3.3#TRPBF | PRODUCTION | |
| LT3973IMSE-5#PBF | PRODUCTION | |
| LT3973IMSE-5#TRPBF | PRODUCTION | |
|
Feb 4, 2020 - 20_0130 Laser Top Mark Conversion for 10-Lead MSOP Packages Assembled in ADPG and UTAC |
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| LT3973EMSE#PBF | PRODUCTION | |
| LT3973EMSE#TRPBF | PRODUCTION | |
| LT3973EMSE-3.3#PBF | PRODUCTION | |
| LT3973EMSE-3.3#TRPBF | PRODUCTION | |
| LT3973EMSE-5#PBF | PRODUCTION | |
| LT3973EMSE-5#TRPBF | PRODUCTION | |
| LT3973HMSE#PBF | PRODUCTION | |
| LT3973HMSE#TRPBF | PRODUCTION | |
| LT3973HMSE-3.3#PBF | PRODUCTION | |
| LT3973HMSE-3.3#TRPBF | PRODUCTION | |
| LT3973HMSE-5#PBF | PRODUCTION | |
| LT3973HMSE-5#TRPBF | PRODUCTION | |
| LT3973IMSE#PBF | PRODUCTION | |
| LT3973IMSE#TRPBF | PRODUCTION | |
| LT3973IMSE-3.3#PBF | PRODUCTION | |
| LT3973IMSE-3.3#TRPBF | PRODUCTION | |
| LT3973IMSE-5#PBF | PRODUCTION | |
| LT3973IMSE-5#TRPBF | PRODUCTION | |
|
Oct 11, 2022 - 22_0244 Epoxy Change from Henkel 8290 to 8290A for MSOP Package |
||
| LT3973IMSE#PBF | PRODUCTION | |
| LT3973IMSE#TRPBF | PRODUCTION | |
|
Jul 12, 2022 - 22_0157 UTAC Thai Limited (UTL) as Alternate Assembly Site for MSOP Packages [With Modification in BOM] |
||
| LT3973IMSE#PBF | PRODUCTION | |
| LT3973IMSE#TRPBF | PRODUCTION | |
|
Jun 21, 2022 - 22_0050 UTAC Thai Limited (UTL) as Alternate Assembly Site for MSOP Packages / Devices |
||
| LT3973IMSE#PBF | PRODUCTION | |
| LT3973IMSE#TRPBF | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
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Request a Driver/SoftwareHardware Ecosystem
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Tools & Simulations
LTspice 1
Models for the following parts are available in LTspice:
- LT3973
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.