LT3971
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LT3971

38V, 1.2A, 2MHz Step-Down Regulator with 2.8μA Quiescent Current

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Info: : PRODUCTION tooltip
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Part Details
Part Models 28
1ku List Price Starting From $3.31
Features
  • Ultralow Quiescent Current: 2.8μA IQ Regulating 12VIN to 3.3VOUT
  • Fixed Output Voltages: 3.3V, 5V, 2.1μA IQ Regulating 12VIN to 3.3VOUT
  • Low Ripple Burst Mode® Operation: Output Ripple < 15mVP-P
  • Wide Input Voltage Range: 4.3V to 38V
  • 1.2A Maximum Output Current
  • Adjustable Switching Frequency: 200kHz to 2MHz
  • Synchronizable Between 250kHz to 2MHz
  • Fast Transient Response
  • Accurate 1V Enable Pin Threshold
  • Low Shutdown Current: IQ = 700nA
  • Power Good Flag
  • Soft-Start Capability
  • Internal Compensation
  • Output Voltage: 1.19V to 30V
  • Small Thermally Enhanced 10-Lead MSOP, 16-Lead MSOP and (3mm × 3mm) DFN Packages
Additional Details
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The LT3971 is an adjustable frequency monolithic buck switching regulator that accepts a wide input voltage range up to 38V. Low quiescent current design consumes only 2.8μA of supply current while regulating with no load. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping the output ripple below 15mV in a typical application. An internally compensated current mode topology is used for fast transient response and good loop stability. A high efficiency 0.33Ω switch is included on the die along with a boost Schottky diode and the necessary oscillator, control and logic circuitry. An accurate 1V threshold enable pin can be used to shut down the LT3971, reducing the input supply current to 700nA. A capacitor on the SS pin provides a controlled inrush current (soft-start). A power good flag signals when VOUT reaches 91% of the programmed output voltage. The LT3971 is available in small 10-lead MSOP and 3mm × 3mm DFN packages with exposed pads for low thermal resistance. A 16-lead MSOP is also offered which has enhanced pin-to-pin fault tolerance.

Vout Iout Vref Accuracy
LT3971 Adj 1.2A 2.5%
LT3971-3.3 3.3V 1.2A 2.5%
LT3971-5 5V 1.2A 2.5%
LT3971A Adj 1.3A 1.5%
LT3971A-5 5V 1.3A 1.5%

Applications

  • Automotive Battery Regulation
  • Power for Portable Products
  • Industrial Supplies
Part Models 28
1ku List Price Starting From $3.31

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Documentation

Documentation

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Part Model Pin/Package Drawing Documentation CAD Symbols, Footprints, and 3D Models
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Product Lifecycle

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Jun 5, 2024

- 24_0003

Epoxy Change from Henkel 8290 to 8290A for MSOP Package (2)

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Oct 11, 2022

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Feb 4, 2020

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Laser Top Mark for 16-Lead MSOP Packages Assembled in ADPG and UTAC

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Jul 12, 2022

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UTAC Thai Limited (UTL) as Alternate Assembly Site for MSOP Packages [With Modification in BOM]

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Jun 21, 2022

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Epoxy Change from Henkel 8290 to 8290A for MSOP Package (2)

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Feb 4, 2020

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Laser Top Mark Conversion for 10-Lead MSOP Packages Assembled in ADPG and UTAC

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Oct 11, 2022

- 22_0244

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Epoxy Change from Henkel 8290 to 8290A for MSOP Package

LT3971EMSE16#PBF

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LT3971IMSE#PBF

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Feb 4, 2020

- 20_0132

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Laser Top Mark for 16-Lead MSOP Packages Assembled in ADPG and UTAC

LT3971EMSE16#PBF

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Jul 12, 2022

- 22_0157

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UTAC Thai Limited (UTL) as Alternate Assembly Site for MSOP Packages [With Modification in BOM]

LT3971IMSE#PBF

PRODUCTION

LT3971IMSE#TRPBF

PRODUCTION

LT3971IMSE-5#PBF

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Jun 21, 2022

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UTAC Thai Limited (UTL) as Alternate Assembly Site for MSOP Packages / Devices

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Software & Part Ecosystem

Software & Part Ecosystem

Evaluation Kit

Evaluation Kits 1

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DC1527A

LT3971EMSE Demo Board | 4.5V ≤ VIN ≤ 38V, VOUT = 3.3V @ 1.2A

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DC1527A

LT3971EMSE Demo Board | 4.5V ≤ VIN ≤ 38V, VOUT = 3.3V @ 1.2A

LT3971EMSE Demo Board | 4.5V ≤ VIN ≤ 38V, VOUT = 3.3V @ 1.2A

Product Detail

Demonstration circuit 1527 is a monolithic step-down DC/DC switching regulator featuring the LT3971. The switching frequency is adjustable up to 2MHz. The demo circuit is designed for 3.3V, 1.2A output from a 4.5V to 38V input. The circuit consumes only 2.8μA of quiescent current.

Tools & Simulations

Tools & Simulations 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.

To launch ready-to-run LTspice demonstration circuits for this part:

Step 1: Download and install LTspice on your computer.

Step 2: Click on the link in the section below to download a demonstration circuit.

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.

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