LT8315 - 560VIN Micropower No-Opto Isolated Flyback Converter with 630V/300mA Switch


  • Wide Input Voltage Range: 18V to 560V
  • 630V/300mA Integrated Power Switch
  • No Opto-Isolator Required for Regulation
  • Quasi-Resonant Boundary Mode Operation
  • Constant-Current and Constant-Voltage Regulation
  • Low-Ripple Light Load Burst Mode® Operation
  • Low Quiescent Current: 70μA
  • Programmable Current Limit and Soft-Start
  • TSSOP Package with High Voltage Spacing

Typical Application

LT8315 Typical Application
LT8315 Typical Application


The LT®8315 is a high voltage flyback converter with integrated 630V/300mA switch. No opto-isolator is needed for regulation. The device samples the output voltage from the isolated flyback waveform appearing across a third winding on the transformer. Quasi-resonant boundary mode operation improves load regulation, reduces transformer size, and maintains high efficiency.

At start-up, the LT8315 charges its INTVCC capacitor via a current source attached to the DRAIN pin. During normal operation, the current source turns off and the device draws its power from a third winding on the transformer.

The LT8315 operates from a wide range of input supply voltages and can deliver up to 15W of power. It is available in a thermally enhanced 20-pin TSSOP package with four pins removed for high-voltage spacing.


For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LT8315EFE#PBF TSSOP-20 FE E 05-08-1990 Yes
LT8315EFE#TRPBF TSSOP-20 FE E 05-08-1990 Yes
LT8315HFE#PBF TSSOP-20 FE H 05-08-1990 Yes
LT8315HFE#TRPBF TSSOP-20 FE H 05-08-1990 Yes
LT8315IFE#PBF TSSOP-20 FE I 05-08-1990 Yes
LT8315IFE#TRPBF TSSOP-20 FE I 05-08-1990 Yes

LT8315 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
LT8315EFE#PBF TSSOP-20 E $5.86 $4.10 Yes
LT8315EFE#TRPBF TSSOP-20 E $5.92 $4.16 Yes
LT8315HFE#PBF TSSOP-20 H $6.79 $4.75 Yes
LT8315HFE#TRPBF TSSOP-20 H $6.85 $4.81 Yes
LT8315IFE#PBF TSSOP-20 I $6.43 $4.50 Yes
LT8315IFE#TRPBF TSSOP-20 I $6.49 $4.56 Yes
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* The USA 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 Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC2337A LT8315EFE Isolated Demo Board | Offline Flyback, 90VAC ≤ VIN ≤ 265VAC, VOUT = 12V @ 0.55A $200.00
DC2478A LT8315 Demo Board | 19V to 400VIN Nonisolated Buck, VOUT = 12V @ Up to 120mA Contact Factory
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Click here to view our complete list of demo boards


  • Isolated Telecom, Automotive, Industrial, Medical Power Supplies
  • Isolated Off Line Housekeeping Power Supplies
  • Electric Vehicles and Battery Stacks

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