Circuit abbreviations

[Ashroyer05]

What does S.S mean? its in the data sheet for SI 8120S. Also what does Vob mean? or maybe it's Vos I can't differentiate. Is that output voltage?

[budm]

Re: Circuit abbreviations

It is 12V regulated output
Vo = Voltage Out
Vos = Voltage output sensing, it is the feedback from the output to maintain the output voltage by sensing to see if the output is too high or too low then it will make the correction to maintain 12V output.
S.S = Soft Start
Connecting a capacitor to terminal no. 5 permits a soft start at poweron.
Delay time Td and rise time Ts can roughly be calculated as
shown below. (However, the values may slightly vary in an actual
application.) If the capacitance of C3 is increased, it takes longer to
discharge C3 after VIN is turned off. Therefore, it is recommended to
set the value within 10mF. When not using the soft start function,
keep terminal no. 5 open.

S.S PIN can also be used of ON/OFF function:
Output ON/OFF control
Output can be turned on and off by using the soft start terminals.
Set the soft start terminal voltage to VSSL (0.2V typ.) or less to stop
output. To switch the potential at the soft start terminals, drive the
open collector of the transistor. Since the discharge current from C3
flows to the ON/OFF control transistor, limit the current for protection.
The SS terminal is pulled up to the power supply in the IC and
no external voltage can be applied.

[Ashroyer05]

Re: Circuit abbreviations

Thanks for the in depth bud. Luckily I understand at least half of that. Can you tell me which one is the out put pin? There is no Vo. Just Vos. Or is the only function of this circuit to provide Vos and no Vo?

[Elysarian]

Re: Circuit abbreviations

SWout (pin 2) is the output pin according to the datasheet I just found.

[budm]

Re: Circuit abbreviations

That is correct, pin 2 is the output pin, you have to measure the DC voltage AFTER the inductor.
If SS pin is grounded, there will be no out put.
So what DC voltage do you get at the input pin, output after the inductor (see application notes on how it is used), SS pin?

[Ashroyer05]

Re: Circuit abbreviations

I have a dead rail of ic's.

[budm]

Re: Circuit abbreviations

Input or output?