1. Products
  2. Power Management
  3. Switching Regulators
  4. Flyback, Forward, and Isolated Controller
  5. LTC3721-1


Features and Benefits

  • High Efficiency Push-Pull PWM
  • 1.5A Sink, 1A Source Output Drivers
  • Adjustable Push-Pull Dead-Time
  • Adjustable System Undervoltage Lockout and Hysteresis
  • Adjustable Leading Edge Blanking
  • Low Start-Up and Quiescent Currents
  • Current Mode Operation
  • Single Resistor Slope Compensation
  • VCC UVLO and 25mA Shunt Regulator
  • Programmable Fixed Frequency Operation to 1MHz
  • Soft-Start, Cycle-by-Cycle Current Limiting and Hiccup Mode Short-Circuit Protection
  • 5V, 15mA Low Dropout Regulator
  • 16-Pin SSOP and (4mm x 4mm) QFN Packages

Product Details

The LTC3721-1 push-pull PWM controller provides all of the control and protection functions necessary for compact and highly efficient, isolated power converters. High integration minimizes external component count, while preserving design flexibility.

The robust push-pull output stages switch at half the oscillator frequency. Dead-time is independently programmed with an external resistor. A UVLO program input provides precise system turn-on and turn off voltages. The LTC3721-1 features peak current mode control with programmable slope compensation and leading edge blanking.

The LTC3721-1 features extremely low operating and start-up currents and reliable short-circuit and overtemperature protection. The LTC3721-1 is offered in 16-pin SSOP and (4mm × 4mm) QFN packages.


  • Telecommunications, Infrastructure Power Systems
  • Distributed Power Architectures
  • Server Power Supplies
  • High Density Power Modules

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.

Tools & Simulations


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.


Models for the following parts are available in LTspice:


Product Recommendations

LTC3721-1 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.View our quality and reliability program and certifications for more information.

Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
LTC3721EGN-1#PBF Material Declaration Reliability Data 16-Lead SSOP (Narrow 0.15 Inch)
LTC3721EGN-1#TRPBF Material Declaration Reliability Data 16-Lead SSOP (Narrow 0.15 Inch)
LTC3721EUF-1#PBF Material Declaration Reliability Data 16-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
LTC3721EUF-1#TRPBF Material Declaration Reliability Data 16-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
Wafer Fabrication Data R302 Reliability Data

PCN-PDN Information

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Sample & Buy

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Buy Now Pricing

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List Pricing

(*)The 1Ku list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.


Lead Times

Please see the latest communication from our CCO regarding lead times.



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