Soft start timings

Hi Nikhil,

It depends on the controller that you are going to use. CSS capacitor selection are usually provided in the Applications Information of the datasheet.

Regards,

Jhun

For LT3072IUFF#PBF, there is no formula mentioned to set the soft-start based on the capacitor value. Can you please tell me the formula?

Hi,

I have already answered this question on your other question.

You can use the formula below in computing for the appropriate soft-start capacitor:

Css=(tss*2uA /0.8V)  F

where in:

Css = capacitance required in Farads(F)

tss = desired soft-start timing in seconds(s)

2uA is the charging current for LTM8051 while 0.8V is its reference voltage for soft-start voltage.

For this instance, you need to change the 2uA and 0.8V depending on the controller you are using.

Regards,

Jhun

HI,

First Of all, sorry for being unclear.

The Current is getting divided in LT3072 LDO. I don't think Reference voltage and Charging Current is that Straight Forward. Can you specify Charging current? The reference voltage is 1.2V if I'm not wrong.

Thanks.

For LT3072, see snipped section below.