TPA2005D1-Q1 Short Circuit Detect

Toshio,

The minimum load ratings give good insight into the current limitations.  The -Q1 datasheet doesn't have these listed, but the catalog version of the datasheet does (it was more recently updated):

It is also important to consider the RDS_on of the outputs FETs:

During a short circuit condition, you can calculate the current using:

I = V/R

I = V/(RDS_ON*2 + R_other)

At 3.6V, the short circuit current is about 3A.  At 5.5V, the short circuit current is about 5.5A.

With a load, the peak current is much less than this.  According to the tables, the peak current will occur at around 4.2V with a 3.2 ohm load, which gives a peak current of about:

I = (4.2V/(2*500mOhms + 3.2 ohms + R_other)

I = 1A