48V Input 3.3V/30A with Output Pre-bias


Design files


This reference design generates a 3.3V/100W output from a standard 48V telecom input and allows for a pre-biased output. The UCC2897A controls operation of the active clamp power stage. The drive signal for the synchronous rectifiers is sent to the secondary side through an ISO7220 digital isolator. This drive signal is blanked out during startup to allow for a pre-biased output. This design achieves efficiencies over 92% and is built on a standard ¼ brick footprint.

Output voltage options PMP5997.1
Vin (Min) (V) 36
Vin (Max) (V) 72
Vout (Nom) (V) 3.3
Iout (Max) (A) 30
Output Power (W) 99
Isolated/Non-Isolated Isolated
Input Type DC
Topology Forward- Active Clamp^Forward- Synchronous

A fully assembled board has been developed for testing and performance validation only, and is not available for sale.

Design files & products

Design files

Download ready-to-use system files to speed your design process.

SLUU614.PDF (2922 K)

Test results for the reference design, including efficiency graphs, test prerequisites and more

SLUR472.PDF (131 K)

Detailed schematic diagram for design layout and components

SLUR473.PDF (64 K)

Complete listing of design components, reference designators, and manufacturers/part numbers


Includes TI products in the design and potential alternatives.


TL331High Voltage Single Differential Comparator

Data sheet document-pdfAcrobat PDF

TL331-EPEnhanced Product Single Differential Comparator

Data sheet document-pdfAcrobat PDF
Digital isolators

ISO7220MDual-channel, 2/0, 150-Mbps digital isolator

Data sheet document-pdfAcrobat PDF open-in-new HTML
Half-bridge drivers

TPS282254-A, 27-V half bridge gate driver with 4-V UVLO for synchronous rectification

Data sheet document-pdfAcrobat PDF open-in-new HTML
PWM controllers

UCC2897A110-V active clamp current mode PWM controller with P-channel clamp FET and line OV protection

Data sheet document-pdfAcrobat PDF open-in-new HTML

Technical documentation

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Type Title Date
Test report PMP5997 Test Results Aug. 16, 2011

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