TPS25910: max reverse current through diode at internal FAT

Hi Katsu,

The body diode of the internal FET is generally not characterized. The max current it can handle depends on the magnitude of current and duration of current. 

Can you let us know how much current you are expecting to flow through the body diode and the duration of it ? 

Hi Praveen-san,

Thank you for your reply.

The current is max 1.2A, and is assumed to be 30 sec to 1 min.

Is there a relation graph of time and current?

Best regards,

Katsu

Hi Katsu,

Unfortunately, we do not have a graph which shows how much current can the body diode withstand for how much time.

Can you let me know if the Enable pin is tied to GND or driven by an external signal ?

In case it is tied to GND and voltage is applied on Vout, the voltage at Vin would be Vout-diode drop. This would enable the device and the FET would be ON Once the FET is ON, the reverse current will flow through the channel of the FET rather than the body diode. In this case the body diode will not be stressed much. 

Hi,

On the customer design, EN is tied to IN with a resistor which makes voltage less than 5V. FET is OFF when Vin is low.

Customer's assumption is that Vout goes up to 7V, so current of 1A flows at body diode from OUT to IN due to FET is OFF.

In this case, can the body diode have any damage or failure?

Best regards,

Katsu