TPS2373: Hotswap FET information.

Hello, 

The TPS2373 has an internal thermal sensor that will shut down the FET if it gets too hot.  This will protect the MOSFET. 

This does mean that the FET will shut down during start-up if the customer uses a huge bulk capacitor.  Once it cools off it will continue to charge the cap.  For a very large cap you may have several "hic-cup" cycles before turning on. 

We don't have a specific "max cap value", but our TPS2373-4 EVM uses a 100uF cap and it has no issues at start-up. 

What capacitor value is your customer looking at? 

-Artem 

Hi Artem

Thank you for reply.
Customers are trying to set about 220uF.
It will be a value larger than 100uF, is there a problem?

Regard
T Kishi

Hi Artem

I am sorry for the request again.
The following conditionsIs it possible to provide a maximum capacity value?
Input 57V, Ta = 85 ° C

Regard
T Kishi

I don't think we have a result for 85C, but you'll likely hit OTSD with 220uF at 85C. My expectation is that you'll hit OTSD with a cap that is in the 150uF to 200 uF at 85C.

However, you can keep the DC/DC off in case of hiccup. If you used advanced start-up feature of TPS2373-4 it will not charge the VCC of the DC/DC until the bulk cap is charged. We have made our TPS2373-4 EVM work with 1mF.

Hi Artem

It would be helpful if you could contact us without data.
In other words, is it possible that OTSD will work, but is it correct with the understanding that TPS2373 can get up normally?
If so, is there no problem with such a way of rising?

Regard
T Kishi

Hi Artem

Thank you for reply.

Please  one more check thing.

In other words, is it good enough to understand that the internal HotSwapFET will not be damaged by

inrush current or overcurrent at startup because the TPS2373 works with OTSD?

Does TPS2373 have no data like attached?

Transient Thermal Impedance.pdf

Regard

T Kishi