Save to MyST

AC-DC Converters

Overview
Documentation
Tools and Software
Solutions
In a typical AC-DC switch mode power supply (SMPS), the AC mains is rectified and filtered to feed a power factor correction (PFC) stage. Then, by means of high-frequency modulation techniques – sometimes in excess of 1 MHz to reduce size of transformers and inductors – it is then delivered to a DC load with the desired voltage and current ratings.  To find the best solution for their applications, designers have to choose the best power topology – fly-back, buck, or quasi-resonant – or the implementation – based on highly integrated converters or with discrete power switches and controllers – or even decide to use an advanced digital implementation.

Buck and Buck-Boost Converter

Off-line converters based on buck, or step-down, and buck-boost, or step-down/up, topologies convert the mains to a regulated DC output, either positive or negative, without the need for an isolation transformer by modulating the duty cycle of the po
View application

Flyback Converter

In its various implementations including primary side and secondary side regulation, fixed switching frequency or quasi resonant operation, an isolated or non-isolated flyback topology is most often found in off-line converters for an output power ra
View application

Forward Converter

The single-switch forward converter represents a valid alternative to the single-switch flyback topology in isolated, off-line, step-down converters with high output current requiring galvanic isolation in the 100 to 300 W power range.
View application

LLC Resonant Converter

The LLC converter is a resonant inverter with three reactive elements where the DC input voltage is turned into a square wave by a switch network arranged as either a half- or full-bridge to feed the resonant LLC tank that effectively filters out har
View application

PFC Converter - Single Phase Input

Power Factor Correction aims at shaping input current to be as sinusoidal as possible, in order to reduce harmonic distortion and its associated losses, and bring power factor close to one in AC circuits.  Placed at the front end of relatively high-p
View application

PFC Converter - Three Phase Input

Power Factor Correction is a technique of shaping input current to be as sinusoidal as possible to reduce harmonic distortion and associated losses and in-phase with input voltage in an AC circuit to have a power factor close to one. Placed as a fron
View application

PS ZVS FB Converter

In a phase-shifting, zero voltage switching full-bridge converter, the two legs of the full-bridge are switched with two square waves whose phase shift is modulated by the converter’s control loop and the resulting square wave is fed into the primary
View application

Two Switch Flyback Converter

In a two-switch flyback topology, a high-side power MOSFET – placed between the input voltage rail and the transformer – and snubber diode are added to help overcome the limitations of conventional flyback topology as the overall voltage stress is eq
View application

Two Switch Forward Converter

In a two-transistor forward the two transistors of the primary are switched on and power is transferred to the secondary winding of the transformer and then to the output capacitor and the load. When switched off, the diodes in the primary clamp the
View application

Our products and solutions

Whatever their choice, the right semiconductor products are key to meeting their specific design targets. ST’s broad product portfolio includes highly-integrated AC-DC converters and controllers, silicon and silicon carbide (SiC) power MOSFETs and rectifiers, IGBTs, protection ICs and specifically designed digital controllers and STM32 microcontrollers. We also provide a comprehensive range of hardware and software evaluation and development tools including our eDesignSuite that helps engineers design high efficiency power supplies and converters.