LT3689
LT3689-5
Info: : PRODUCTION
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LT3689
LT3689-5

700mA Step-Down Regulator with Power-On Reset and Watchdog Timer

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Info: : PRODUCTION tooltip
Info: : PRODUCTION tooltip
Part Details
Part Models 20
1ku List Price Starting From $3.49
Features
  • Wide Input Range:
    • Operation from 3.6V to 36V
    • Overvoltage Lockout Protects Circuits through 60V Transients
  • 85μA IQ at 12VIN to 3.3VOUT
  • Low Ripple Burst Mode® Operation Allows Output Ripple <15mVP-P
  • Programmable, Defeatable Watchdog Timer with Window or Timeout Control
  • Programmable Power-On Reset Timer (POR)
  • Synchronizable, Adjustable 350kHz to 2.2MHz Switching Frequency
  • 700mA Output Switching Regulator with Internal Power Switch
  • Fixed 5V or Adjustable Output Voltage
  • 800mV Feedback Voltage
  • Programmable Input Undervoltage Lockout with Hysteresis
  • 16-Pin 3mm × 3mm QFN and 16-Pin MSOP Packages
Additional Details
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The LT3689 is an adjustable frequency (350kHz to 2.2MHz) monolithic step-down switching regulator with a power-on reset and watchdog timer. The regulator operates from inputs up to 36V and withstands transients up to 60V. Low ripple Burst Mode® operation maintains high efficiency at low output current while keeping output ripple below 15mV in a typical application, with input quiescent current of just 85μA. Shutdown circuitry reduces input supply current to less than 1μA while EN/UVLO is pulled low. Using a resistor divider on the EN/UVLO pin provides a programmable undervoltage lockout. Current limit, frequency foldback and thermal shutdown provide fault protection.

The reset and watchdog timeout periods are independently adjustable using external capacitors. Tight accuracy specifications and glitch immunity ensure reliable reset operation of a system without false triggering. The open collector RST will pull down if output voltage drops 10% below the programmed value. The watchdog timer is pin-selectable for window or timeout modes. In timeout mode, WDO pulls low if too long of a period passes before a watchdog transition is detected. In window mode, the LT3689 monitors for WDI falling edges grouped too close together or too far apart.

Applications

  • Automotive Electronic Control Units
  • Industrial Power Supplies
Part Models 20
1ku List Price Starting From $3.49

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Documentation

Documentation

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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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PRODUCTION

Oct 11, 2022

- 22_0244

arrow down

Epoxy Change from Henkel 8290 to 8290A for MSOP Package

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PRODUCTION

LT3689HMSE-5#TRPBF

PRODUCTION

LT3689IMSE#PBF

PRODUCTION

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PRODUCTION

Apr 18, 2022

- 22_0050

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

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PRODUCTION

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Software & Part Ecosystem

Software & Part Ecosystem

Evaluation Kit

Evaluation Kits 1

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DC1312A

LT3689EUD Demo Board | 4.5V ≤ VIN ≤ 36V (60V Transients), VOUT = 3.3V @ 700mA

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DC1312A

LT3689EUD Demo Board | 4.5V ≤ VIN ≤ 36V (60V Transients), VOUT = 3.3V @ 700mA

LT3689EUD Demo Board | 4.5V ≤ VIN ≤ 36V (60V Transients), VOUT = 3.3V @ 700mA

Product Detail

Demonstration circuit 1312 is a monolithic 700mA step-down regulator withpower-on reset and watchdog timer featuring the LT3689. The board operates with inputs from 4.5V up to 36V and withstands transients up to 60V. The output is 3.3V, 700mA. The power-on reset and watchdog timer periods are independently adjustable using external capacitors.



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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