STEVAL-ISA019V2: 80W, 24V @ 3.3A, 160 ~ 550VAC


The purpose of this application note is to explain the design of an 80 W 3-phase auxiliary power supply for motor drives and welding applications. To reach a high level system in terms of both efficiency and cost, the L6565 PWM controller has been selected as well as the STC04IE170HV as the main switch. The combination of these STMicroelectronics parts provides a highly efficient solution for high DC input voltage, a typical requirement of any three-phase application.

The L6565 driver is a variable frequency PWM driver suitable for a design flyback converter working in quasi-resonant mode. It also includes some very useful additional features.

All the design choices are thoroughly discussed to allow the user to adapt the project to specific needs. The input voltage can also be extended up to 1000 VDC as enough margin exists to do so. Finally, the experimental results are analyzed to better understand the benefits offered by the use of ESBT in this application.

* Based on eval Board STEVAL-ISA019V2


Manufacturer STMicroelectronics
Category AC/DC and DC/DC Conversion
Sub-Category AC/DC SMPS - Single Output
Eval Board Part Number 497-6339-ND
Eval Board Supplier STMicroelectronics
Eval Board -
AC Voltage 115 V
230 V
Universal (115 / 230V)
Outputs and Type 1 Isolated
Voltage Out 24 V
Current Out 3.3 A
Output Power 80 W
Features Over Current Protection
Under Voltage Protection, Brown-Out
Efficiency @ Conditions >80%, 250V in, 24V @ 20 ~ 80 W Out
>75%, 850V in, 24V @ 25 ~ 80 W Out
No-load Input Power @ Voltage
Switching Frequency 50 kHz
Internal Switch No
Component Count + Extras 58 + 2
Voltage In 160 ~ 550 VAC
Design Author STMicroelectronics
Application / Target Market Auxiliary Power Supply
Welding Machines
Main I.C. Base Part L6565

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