[moved] LED Tube Driver (non isolated design)

[Pronay088]

Hi,
I am working on a led tube driver circuit sample.
Basically I am trying to reversing the circuit just for simulation purpose. So, the basic blocks of the circuit consists of: AC input - Bridge rectifier - EMI filtering - Buck Converter - Controller IC for Buck - Output.

Now, I am having trouble finding the controller IC, which is a 6 pin SMD, with a marking "BA 516". By far I searched every smd catalog I own, but got disappointed.
Analyzing the circuit configuration I figured out the possible pin function of the IC and assuming its a PWM controller IC (I maybe wrong) for buck converter switching gate (mosfet) signal.

Here I attached a schematic of the circuit. You can see, I tried to guess the pin name of the IC (BA 516). Please suggest the proper specification/datasheet of the IC or any alternative IC that can do the work!

N.B.: Its my first thread! So let me know if I am doing anything wrong!

Thanks.

 

[treez]

it looks like its trying to be a tapped inductor buck converter, but there is a connection from ground to the fet source, so that cant be right. I don't see how it can be nfet as their is no boosted drive voltage.

 

[treez]

it looks like a poor design to me, way too many components for a 6w led driver.
It looks like a tapped inductor, though that schematic doesn't seem to take advantage of the "tapped inductor buck converter" principle.
BA 516 it could be anything, many of the far eastern ic's don't have publicly available datasheets.

 

[Pronay088]

it looks like its trying to be a tapped inductor buck converter, but there is a connection from ground to the fet source, so that cant be right.

Yeah this connection bothered me too!

 

[Pronay088]

It looks like a tapped inductor, though that schematic doesn't seem to take advantage of the "tapped inductor buck converter" principle. BA 516 it could be anything, many of the far eastern ic's don't have publicly available datasheets.

I thought the tapping is just an auxiliary PS for IC, to keep it running while the circuit do it's own work. Actually I am looking for an alternative for BA516, the rest of the circuit can be developed later.

 

[treez]

I thought the tapping is just an auxiliary PS for IC

yes sorry you are right.
I know power integrations do some good led drivers like that, with lower component count