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solve issue for lyt4227E of 50 watt design

Posted by: sales.sunhari1 on

hello ,

i have problem in lyt4227e 50 watt design that if i use 47uf capacitor on v pin than not got perfectly 1.2a but if i use 4.7uf capacitor i perfectly got 1.2a please solve my issue what is best for my design i attched hear...........

 

and what is best for my circut 1.2a 36 volt load can i drive for 64 watt

and how it convert 600mA 72 volt design 

 

 

Files

Attachment Size
50WATT-LED-DRIVER.png 108.05 KB

Comments

Submitted by PI-Crumb on 07/27/2016

hi,

Is it Vpin or BP pin? BP pin sets the current limit. 4.7 uF capacitor will provide higher current limit. If you design using PIXLS, then if the current limit mode was set to FULL, then you should use 4.7 uF.

Please utilize PIXLS on you other designs. Let me know if you have any trouble using the software.

Submitted by sales.sunhari1 on 07/27/2016

In reply to by PI-Crumb

hello sir ,

for low heating what is consider 4.7uf or 47uf

 

if i use 4.7uf with R11-68k and R7=120k than i got 1.2A

but when use 47uf i am not get 1.2A proper 

please find my attchment hear...

Attachment Size
schematic 108.05 KB
Submitted by PI-Crumb on 08/02/2016

hi,

Using either 4.7 uF or 47 uF does not affect the thermal performance of the device. Some designs, however, require higher current limit, and your design is one of them.

The schematic does not indicate exactly what is the bias voltage on your design. I would have wanted to check the PIXLS, but after doing a design with your  parameters, it looks like the design is based on full current limit. This is why you can get 1.2A on 4.7uF but not on 47 uF.

Submitted by sales.sunhari1 on 09/02/2016

i use  at bp to fb pin 4.7uf  with 10uf/63 volt + 120k + 68K i got 1.2A but the driver ic is too much heat and after that circut is off after few minutes

i use  at bp to fb pin 47uf  with 10uf/63 volt + 100k + 39K i not got 1.2A  i got 1.10-1.16A but the driver ic is too much heat and after that circut is off aftersome minutes more than i use 4.7uf what is issue in this driver 

and watts also decres after few minutes 

i attached both schematic and transformer design please find hear

sales.sunhari1@gmail.com

7227061234

 

Attachment Size
transformer 1.08 MB
schematic 108.05 KB
Submitted by PI-Crumb on 09/08/2016

Did you use a heatsink? If not, please add a heatsink. At 50W, LYT-4 may need heatsink.

Submitted by sales.sunhari1 on 09/09/2016

yes sir i use heat sink at ic and byQ200 both on i use heatsink

Submitted by PI-Crumb on 09/13/2016

Please check the drain current and voltage and find out if there is any sign of abnormality such as transformer saturation or excessive leakage. I advise you to review your transformer design if that's the case.