3.3V/15A Active Clamp Forward Reference Design
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Key Document


This reference design is a 50W active clamp forward converter with synchronous rectification on the secondary side. The design provides an isolated, 3.3V/15A output from a standard telecom -36V to -72V input at >91% efficiency. PMP20850 utilizes a self driven, synchronous rectifier which requires no secondary gate driver which minimizes cost and improves efficiency. This device also features programmable dead-time, which is fine tuned to maximize efficiency of the design. Output voltage regulation is based on current mode control, simplifying loop compensation. PMP20850 features a catalog transformer, minimizing the cost of magnetics in the design.

  • >90% efficiency with 15A load across full input voltage range
  • Self driven synchronous rectifier eliminates need for secondary gate drivers
  • Catalog transformer minimizes cost of magnetics

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(Output Voltage 1)
Vin (Min) (V)-72
Vin (Max) (V)-36
Vout (Nom) (V)3.3
Iout (Max) (A)15
Output Power (W)49.5
Input TypeDC
TopologyForward- Active Clamp

TI Devices (3)

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Part Number Name Product Family Sample & Buy Design Kits & Evaluation Modules
CSD16414Q5  25V, N ch NexFET MOSFETâ„¢, single SON5x6, 2.6mOhm  MOSFETs  Sample & Buy Not Available
TLV431A  1% accuracy, low-voltage, adjustable precision shunt regulator  Voltage references  Sample & Buy View Design Kits & Evaluation Modules
UCC2897A  110-V active clamp current mode PWM controller with P-channel clamp FET and line OV protection  Offline & isolated DC/DC controllers & converters  Sample & Buy View Design Kits & Evaluation Modules

CAD/CAE symbols

Part # Package | Pins CAD File (.bxl) STEP Model (.stp)
CSD16414Q5 Download Download
TLV431A Download Download
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UCC2897A Download Download
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Technical documentation

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User guides (1)
Title Type Size (KB) Date
PDF 1860 19 Jun 2017
Design files (6)
Title Type Size (KB) Date
ZIP 388 19 Jun 2017
ZIP 1154 19 Jun 2017
PDF 541 19 Jun 2017
PDF 114 19 Jun 2017
PDF 65 19 Jun 2017
PDF 128 19 Jun 2017

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