18-VDC - 30-VDC input multiple output flybuck reference design
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Key Document


This isolated flybuck reference design uses the LM3150 synchronous buck controller to generate one non-isolated output (3.3 V at 5 A) and two isolated outputs (5 V at 100 mA, 5 V at 100 mA) from a DC input (18 VDC - 30 VDC). The design can provide 17.5-W output power. Two additonal linear regulator LP2922A improve the regulation of the isolated outputs.

  • Primary side regulation without optical-coupler
  • Achieves over 90% peak efficiency
  • Compact and cost effective isolated solution
  • Constant on-time architecture which needs no loop compensation

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Design Files

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(Output Voltage 1)
(Output Voltage 2)
(Output Voltage 3)
Vin (Min) (V)181818
Vin (Max) (V)303030
Vout (Nom) (V)3.355
Iout (Max) (A)5.1.1
Output Power (W)
Input TypeDCDCDC

TI Devices (2)

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Part Number Name Product Family Sample & Buy Design Kits & Evaluation Modules
LM3150  6V to 42V Synchronous Step-Down Controller with Adjustable Output Voltage  Step-down (buck) regulators  Sample & Buy View Design Kits & Evaluation Modules
LP2992  250-mA, 16-V, low-dropout voltage regulator with enable  Power management  Sample & Buy View Design Kits & Evaluation Modules

CAD/CAE symbols

Part # Package | Pins CAD File (.bxl) STEP Model (.stp)
LM3150 Download Download
LP2992 Download Download
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Technical documentation

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User guide (1)
Title Type Size (KB) Date
PDF 13471 21 Dec 2018
Design files (5)
Title Type Size (KB) Date
ZIP 102 21 Dec 2018
PDF 220 21 Dec 2018
PDF 194 21 Dec 2018
PDF 28 21 Dec 2018
PDF 127 21 Dec 2018

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