1. Products
  2. Power Monitor, Control, and Protection
  3. Power Control
  4. Offline Power Factor Correction (PFC) Controllers
  5. LT1509


Features and Benefits

  • PFC and PWM Single Chip Solution
  • Synchronized Operation up to 300kHz
  • 99% Power Factor over 20:1 Load Current Range
  • Current Mode PWM
  • Instantaneous Overvoltage Protection
  • Dedicated Overvoltage Protection (OVP Pin)
  • Minimal Line Current Dead Zone
  • Typical 250µA Start-Up Supply Current
  • Line Switching Noise Filter
  • Low Quiescent Current: 13mA
  • Fast 2A Peak Current Gate Drivers
  • Separate Soft Start Controls

Product Details

The LT1509 is a complete solution for universal off-line switching power supplies utilizing active power factor correction. The PFC section is identical to the LT1248 PFC controller except the EN/SYNC pin is removed because PFC and PWM are synchronized internally.

The current mode PWM section (the LT1508 is the volt-age-mode counterpart) contains all the primary side functions to convert the PFC preregulated high voltage output to an isolated low voltage output. The PWM duty cycle is internally limited to 47% (maximum 50%) to prevent transformer saturation. PWM soft start begins when PFC output reaches the preset voltage. In the event of brief line loss,the PWM will be shut off when the PFC output voltage drops below 73% of the preset value.


  • Universal Power Factor Corrected Power Supplies and Preregulators

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

LT1509 Companion Parts

Recommended Related Parts

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
LT1509CN#PBF Material Declaration Reliability Data 20-Lead PDIP (Narrow 0.3 Inch)
LT1509CSW#PBF Material Declaration Reliability Data 20-Lead SOIC (Wide 0.3 Inch)
LT1509CSW#TRPBF Material Declaration Reliability Data 20-Lead SOIC (Wide 0.3 Inch)
LT1509IN#PBF Material Declaration Reliability Data 20-Lead PDIP (Narrow 0.3 Inch)
LT1509ISW#PBF Material Declaration Reliability Data 20-Lead SOIC (Wide 0.3 Inch)
LT1509ISW#TRPBF Material Declaration Reliability Data 20-Lead SOIC (Wide 0.3 Inch)
Wafer Fabrication Data R389 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

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