The circuit operates from 85Vac to 264Vac input voltage with an output power peak of 6W through two output voltages of 5Vdc and 12Vdc. It contains an input fuse (F2), EMI filtering (C1, L1, and C2), and the secondary regulation is provided by U2 and U3, the optocoupler and TL431 respectively.
An additional LC (PI) filter is added to the 5Vdc output, C9-L2 configuration, for further effective ripple and noise rejection. The AC input is rectified and filtered by the bridge BR1 and the bulk capacitor C1 to generate the high voltage DC bus applied to the primary winding of the transformer, T1.
The 5Vdc output is sensed with an optocoupler. It is possible to modify the output voltages by changing the transformer turns ratio and modifying the resistance values of R7 and R8 in the feedback loop. R2 and C4 form the snubber circuit needed to reduce the voltage ringing on the drain pin and the leakage spikes.
Manufacturer | STMicroelectronics |
---|---|
Category | AC/DC and DC/DC Conversion |
Sub-Category | AC/DC SMPS - Multi Output |
Eval Board Part Number | 497-4931-ND |
Eval Board Supplier | STMicroelectronics |
Eval Board |
Board not Stocked
|
AC Voltage |
115 V
230 V Universal (115 / 230V) |
Outputs and Type |
2 Isolated
|
Voltage Out: Highest Current First |
12V, 5V
|
Current Out |
600mA, 250mA
|
Output Power |
6 W
|
Efficiency @ Conditions |
>79%, 220V in, Full Load
>76%, 120V in, Full Load |
No-load Input Power @ Voltage |
153 mW @ 115 V
222 mW @ 230 V |
Features |
Energy Standard Compliant
Light Load Mode Over Current Protection Over Voltage Protection Short Circuit Protection Thermal Protection Under Voltage Protection, Brown-Out Zero Load Regulation |
Switching Frequency |
60 kHz
|
Internal Switch |
Yes
|
Component Count + Extras |
30 + 4
|
Voltage In |
85 ~ 265 VAC
|
Application / Target Market |
Power: AC Adapters
Set-Top Boxes Telecom White Goods |
Design Author |
STMicroelectronics
|
Main I.C. Base Part |
VIPer12A
|
Date Created By Author | |
Date Added To Library | 2011-03 |