Question on this ic

[lorins_core]

what is a different between RT8206A and RT8206B?

Thanks

[meritosari]

Re: Question on this ic

Pin 20, SecFB, Secondary Feedback

[bluestone]

Re: Question on this ic

they are the same

[meritosari]

Re: Question on this ic

AFAIK, RT8206A/B has same function for LDO+SMPS 3V and 5V, but for RT8206A has special function at pin 20 ie SecFB.

We all know from datasheet that provided by Richtek. According from datasheet then we know "How it work" the IC in-circuits.

I think there is different use depending of desaign motherboard. Compare 3 board whose use RT8206A and Rt8206B, found a little different purpose in dis-charge circuit. Asus N73SV, Quanta ZQ9, Compal LA-4493P. (Click to get schematic)

Dis-charge circuit is used when to "power on" and pure "shutdown" on laptop

Asus N73SV, +12VSUS from charge pump monitoring by secfb (regulator has resistor divider, Page 81 and other purpose as load switch, Page 91, use RT8206A, common found on asus mobo)

ZQ9, +15V line there is no feedback (no resistor divider on regulator Page 37, circuit dis-charge page 43, use RT8206B)

LA-4493P, in-circuit compal not using from charge pump, but it using from VSB (pin 20, NC=not connected page 46, DC interface, Page 42, use equivalent chip ISL6237)

I'm type who playing safe, Right now so easy to get both the IC or equivalent, whether RT8206A/B or equvalent, so its not make sense for me to practice that have a bit risk.

Finally this only in my opinion, so can be wrong.