TPS22810: Is local input capacitance required or optional?

Jonathan Bender

Part Number: TPS22810

Hello,

I'm looking at using TPS22810 for a 12V daughtercard application, I_LOAD < 1A. The daughtercard has 20 uF of capacitance on the 12V input, and I want TPS22810 to isolate that so I don't get a large inrush current upon connection. Similarly, I don't want any local capacitance on TPS22810's VIN. The datasheet describes the input capacitor as optional in section 10.3, but is a 1 uF recommended minimum in Table 7.3.

Can I use TPS22810 with no local CIN, or perhaps 0.1 uF? The 12V bus it's plugging into has some capacitance on it, probably 10s of uF, so I'm wondering if that would satisfy the requirement.

Thanks,

Jonathan

over 7 years ago

0 Aleksandras_Kaknevicius over 7 years ago

TI__Genius 15780 points

Hi Johnathan,

The input capacitance is not required for the switch to function, the main purpose of the capacitance is to help the power supply to handle any output transients without having system supply droop. I think the bulk capacitance on the bus should help satisfy that recommendation.

Thanks,

Alek Kaknevicius

0 Jonathan Bender over 7 years ago in reply to Aleksandras_Kaknevicius

TI__Expert 7895 points

Hi Alek,

Great, thanks for the quick reply!

Jonathan

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TPS22810: Is local input capacitance required or optional?