ASL1500 boost output voltage is unstable while the load is turned on

[Guofred]

Hi,

ASL1500 boost output voltage is unstable while the load is turned on, the details as below.

solution: ASL1500+ASL2416   LED load 38W

ASL1500 Hardware parameter:

1) boost output voltage is 50V

2)boost frequency is 380Khz

3)VGG is around 7V

4)inductor  value is around 33uH

5)the Resistor sense is 0.005ohm

6)the boost capacitor is around 33uF

would you like to share your comments, thanks.

Best regards.

Guofred

[TomasVaverka · Accepted solution]

Hi Guofred,

From these scope shots it is difficult to say what is going on.

Could be something around the SPI settings for the loop, the sequence around the turn on. But I am not sure about this.

I would more suspect something around the external part like the power supply on the input filter of the system.

We do have a local AE for Auto LED drivers in China, perhaps I could connect you with him, just let me know.

Best regards,

Tomas 

[Guofred]

Hi @TomasVaverka ,

Thanks for your kindly help.

1) yes, we try to modify the ASL2416 buck input capacitor from 33uF to 200uF,it has a little improvements.

but the capacitor footprint height is upper than the customer requirement, it is difficult to assembly.

so whether is have other ideas for this issue.

2) yes, local AE  Mr.Wen is helping to support this issue, i would like to follow-up his good idea and check the final result again.

Best regards.

Guofred