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Smps design isn't giving enough power

Akshar Vastarpara

Jan 24, 2018
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Jan 24, 2018
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Hello,
As i want to thank you for making this great ic to work on.
Now i might be little beginner in this but i hope some of you can help me it's a very little problem though i am unable to find it.
Now the thing is i have used TNY284PG for one of my project.
I designed it for 3.3V DC 1A output.
And 240V input AC.
We have connected small leds of 3.3v to it more than 50.
Now what happens all 50 of them only consumpts 170ma current. Now if i will add up more they will not get lit up.if i will substract from previous leds than new leds will light up.
So basically whole power supply thing do not exceed above 170ma current.
I am providing below the schematics if you can help me.
 

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davenn

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Sep 5, 2009
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I am providing below the schematics if you can help me.


cant read any of the values on the schematic
crop down the image so it only shows the schema. and not all the other stuff
resize upwards if you have to, to around 1024 x 768
 

Harald Kapp

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Nov 17, 2011
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I designed it for 3.3V DC 1A output.
Your schematic shows a 16 V output and a 3.3 V output. What is the actual load on the 16 V ouput?

How are the LEDs connected? At 16 V output voltage surely some are in series, some in parallel. There also need to be current limiting resistors. Show us the full diagram, please.

Also check your schematic. The datasheet shows a capacitor in parallel to D2 and a resistor in series between D2 and D4 (component identifiers from your schematic).
The datasheet also states a peak output power of 10.9 W for this IC. At 16 V * 1 A plus 3.3 V * 1 A you exceed the peal output power by 8.4 W.
 
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