Other Parts Discussed in Thread: LM3409
Tool/software:
I am trying to solve the issue that current flows through R, G, B depending on the condition of the Sync pin even when DAC Limit 0, 0, 0 of R, G, B is input through TPS99001.
Specifically, when Sync period 30 code, Sync pulse width 3 code is applied to LM3409 from TPS99001 and 18V is applied to the power of LM3409 and the current is checked, it is confirmed that current flows through R, G, B.
In that time, Average current is 226uA
I wondered if there was a power shortage at the switching moment of LM3409, so I set the power from 18V to 28V and checked. When I applied DAC Limit 0, 0, 0 and Sync period 30code, sync pulse width 3 code to R, G, B, I confirmed that the amount of current flowing decreased.(226uA →146uA)
On the other hand, when I reduced the power to 11V, Average current increased.(226uA →146uA→368uA)
It seems that there is a limit to controlling the Sw frequency with the Sync pin,
and what remains is power control. Is this phenomenon due to a lack of power?
Also, can this phenomenon be improved by using another CCM DC/DC Converter?
Also, in this case, are there any products you would recommend that I apply when making an improvement board?
