LM22670,LM22677...

Jorge Tornero

Other Parts Discussed in Thread: LM22677, LM22670

Hello Mr/Ms,

I will use LM22670-adj in topology Buck and inverter together with LM22677 in buck topology (3x CI LM22670 as buck, two CI LM22670 inverter, and one LM22677 as buck). I want to use the pin sync in all CI and I want to know if that is possible and how contect it. or only I have to attach the pin sync of all integrated circuits and one resistor to 1K to gnd like figure 4 (self synchronizing setup) of LM22670.

Thank you and best regards Jorge

over 11 years ago

0 Juan Paulo Fung over 11 years ago

TI__Expert 3840 points

Hi Jorge - I'll be forwarding your question to the correct Apps Engineer. Expect a reply soon.

Best Regards,

-JPF

0 Frank De Stasi over 11 years ago in reply to Juan Paulo Fung

TI__Guru 64365 points

You can connect all of the buck regulators together to a common sync line. However, the inverting

regulator will have its ground floating. In that case you will have to level shift the sync signal or use

capacitive coupling.

F.D.

0 Jorge Tornero over 11 years ago in reply to Frank De Stasi

Prodigy 90 points

Thank you Frank

I will try it by coupling a capacitor in the pin sync in inverter topology.

Best regards

0 Jorge Tornero over 11 years ago in reply to Jorge Tornero

Prodigy 90 points

I've tried placing a 10nF capacitor on the sync pin in the inverter dc-dc for block continuous voltage, and it works ok together with the non-inverting

thanks to all

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LM22670,LM22677...