Features and Benefits

  • VIN and VOUT Limited Only by External Components
  • 4.5V Undervoltage Lockout Threshold
  • Adjustable Slope Compensation
  • Adjustable Overcurrent Protection with Automatic Restart
  • Adjustable Operating Frequency (70kHz to 700kHz) With One External Resistor
  • Synchronizable to an External Clock
  • ±1.5% Reference Accuracy
  • Only 100mV Current Sense Voltage Drop
  • RUN Pin with Precision Threshold and Adjustable Hysteresis
  • Programmable Soft-Start with One External Capacitor
  • Low Quiescent Current: 360μA
  • Small 10-Lead MSOP and 3mm × 3mm DFN

Product Details

The LTC3805-5 is a current mode DC/DC controller designed to drive an N-channel MOSFET in flyback, boost and SEPIC converter applications. Operating frequency and slope compensation can be programmed by external resistors. Programmable overcurrent sensing protects the converter from overload and short-circuit conditions. Soft-start can be programmed using an external capacitor and the soft-start capacitor also programs an automatic restart feature.

The LTC3805-5 provides ±1.5% output voltage accuracy and consumes only 360μA of quiescent current during normal operation and only 40μA during micropower startup. Using a 9.5V internal shunt regulator, the LTC3805-5 can be powered from a high VIN through a resistor or it can be powered directly from a low impedance DC voltage from 4.7V to 8.8V.

The LTC3805-5 is available in the 10-lead MSOP package and the 3mm × 3mm DFN package.

Turn On Voltage
LTC3805 8.4V
LTC3805-5 4.5V


  • Automotive Power Supplies
  • Telecom Power Supplies
  • Isolated Electronic Equipment
  • Auxiliary/Housekeeping Power Supplies
  • Power over Ethernet

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Evaluation Kits (2)

Tools & Simulations


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Models for the following parts are available in LTspice:


Product Recommendations

LTC3805-5 Companion Parts

Recommended Suggested Oscillator

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.

PCN-PDN Information

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Evaluation Boards

Pricing displayed is based on 1-piece.

Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.

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.