Features and Benefits

  • VIN and VOUT Limited Only by External Components
  • Adjustable Slope Compensation
  • Internal Soft-Start
  • Constant Frequency 200kHz Operation
  • ±1.5% Reference Accuracy
  • Current Mode Operation for Excellent Line and Load Transient Response
  • No Minimum Load Requirement
  • Low Quiescent Current: 240μA
  • Low Profile (1mm) SOT-23 Package

Product Details

The LTC3803 is a constant frequency current mode flyback controller optimized for driving N-channel MOSFETs in high input voltage applications. Constant frequency operation is maintained down to very light loads, resulting in less low frequency noise generation over a wide range of load currents. Slope compensation can be programmed with an external resistor.

The LTC3803 provides ±1.5% output voltage accuracy and consumes only 240μA of quiescent current. Ground-referenced current sensing allows LTC3803-based converters to accept input supplies beyond the LTC3803’s absolute maximum VCC. A micropower hysteretic start-up feature allows efficient operation at high input voltages. For simplicity, the LTC3803 can also be powered from a high VIN through a resistor, due to its internal shunt regulator. An internal undervoltage lockout shuts down the LTC3803 when the input voltage is too low to provide sufficient gate drive to the external MOSFET.

The LTC3803 is available in a low profile (1mm) 6-lead SOT-23 (ThinSOT) package.

Turn On Voltage Frequency
LTC3803 8.7V 200kHz
LTC3803-3 8.7V 300kHz
LTC3803-5 4.8V 200kHz


  • Telecom Power Supplies
  • 42V and 12V Automotive Power Supplies
  • 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

LTC3803 Companion Parts

Recommended µModule Regulator

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.

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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.