Cost-Effective Transformerless Offline Supply for Light Load Applications (Rev. A)

Texas Instruments

Published Date: 06/16/2015

Description

This design idea provides a simple non-isolated AC/DC power supply for low power applications. The design uses a "capacitive-dropper" front-end combined with a LM46000 SIMPLE SWITCHER® buck regulator from Texas Instruments. The circuit provides 3.3 V at a minimum of 100 mA from a line supply of 90 VAC to 265 VAC. Theory of operation as well as design equations and performance results are given.

Parts

Part Number Name Companion Part
LM2574HVM-12 LM2574HVM-12 Buy Datasheet
LM2574HVM-15/NOPB LM2574HVM-15/NOPB Buy Datasheet
LM2574HVM-5.0 LM2574HVM-5.0 Buy Datasheet
LM2574HVMX-12/NOPB LM2574HVMX-12/NOPB Buy Datasheet
LM2574HVMX-3.3/NOPB LM2574HVMX-3.3/NOPB Buy Datasheet
LM2574HVMX-5.0 LM2574HVMX-5.0 Buy Datasheet
LM2574HVMX-ADJ/NOPB LM2574HVMX-ADJ/NOPB Buy Datasheet
LM2574HVN-ADJ/NOPB LM2574HVN-ADJ/NOPB Buy Datasheet
LM2590HVS-ADJ/NOPB LM2590HVS-ADJ/NOPB Buy Datasheet
LM2590HVSX5.0AQ LM2590HVSX5.0AQ Buy Datasheet
LM2590HVSX5.0AQ/NOPB LM2590HVSX5.0AQ/NOPB Buy Datasheet
LM2591HVS-ADJ/NOPB LM2591HVS-ADJ/NOPB Buy Datasheet
LM2591HVSX-5.0/NOPB LM2591HVSX-5.0/NOPB Buy Datasheet
LM2591HVT-5.0/NOPB LM2591HVT-5.0/NOPB Buy Datasheet
LM2591HVT-ADJ/NOPB LM2591HVT-ADJ/NOPB Buy Datasheet
LM2594HVM-ADJ LM2594HVM-ADJ Buy Datasheet
LM2594HVM-ADJ/NOPB LM2594HVM-ADJ/NOPB Buy Datasheet
LM2594HVMX-3.3/NOPB LM2594HVMX-3.3/NOPB Buy Datasheet
LM2594HVMX-ADJ/NOPB LM2594HVMX-ADJ/NOPB Buy Datasheet
LM2597HVM-5.0/NOPB LM2597HVM-5.0/NOPB Buy Datasheet
LM2597HVM-ADJ/NOPB LM2597HVM-ADJ/NOPB Buy Datasheet
LM2597HVMX-5.0/NOPB LM2597HVMX-5.0/NOPB Buy Datasheet
LM2597HVN-12/NOPB LM2597HVN-12/NOPB Buy Datasheet
LM2597HVN-ADJ/NOPB LM2597HVN-ADJ/NOPB Buy Datasheet