STEVAL-ISA002V1: 6W, 12V @ 500 mA, 85 ~ 265VAC

Summary

This board is designed as a discontinuous flyback regulator delivering 0.5A at 12V. The AC input is rectified and filtered by the bridge BR1, the bulk capacitor C1, and C2 to generate the high voltage DC bus applied to the primary winding (pins 8-10) of the transformer, TR1.

C1, L1, and C2 provide EMI filtering for the circuit. R2 and C3 form the snubber circuit needed to reduce the leakage spike and voltage ringing on the drain pin of VIPer12A. The output voltage is regulated with a TL431 (U3) via an optocoupler (U2) to the feedback pin.

The output voltage ripple is controlled with the capacitor, C7, with an additional LC PI filter configuration made up of L4 and C8. It is possible to modify the output voltages by changing the transformer turns ratio and modifying the resistance values of R6 and R7 in the feedback loop.

* Based on board 497-4930-ND STEVAL-ISA002V1

Specifications

Manufacturer	STMicroelectronics
Category	AC/DC and DC/DC Conversion
Sub-Category	AC/DC SMPS - Single Output
Eval Board	Board not Stocked
AC Voltage	115 V 230 V Universal (115 / 230V)
Outputs and Type	1 Isolated
Voltage Out	12 V
Current Out	500 mA
Output Power	6 W
Features	Light Load Mode Over Current Protection Over Voltage Protection Short Circuit Protection Thermal Protection Under Voltage Protection, Brown-Out Zero Load Regulation
Efficiency @ Conditions	>74% @ Full Load
No-load Input Power @ Voltage	168 mW @ 115 V 248 mW @ 230 V
Switching Frequency	60 kHz
Internal Switch	Yes
Component Count + Extras	28 + 3
Voltage In	85 ~ 265 VAC
Design Author	STMicroelectronics
Application / Target Market	Power: AC Adapters Set-Top Boxes Telecom White Goods
Main I.C. Base Part	VIPer12A
Date Created By Author
Date Added To Library	2011-03