TPS74801: Is it possible to use 2 TPS74801AWDRCR to increase the current capacity by connecting two devices in parallel

Hi Jieyu,

Yes, you can parallel them to obtain more current.  There are two methods available to you.  The TPS74801 does not have an NR/SS pin so you cannot tie the references together, which is typically the dominant source of error between LDO's using method 1.  Thus I tend to prefer Method 2 for this LDO. 

Method 1: Ballast resistors

You can add series ballast resistors to the output of the LDO to increase the current.  The CON of this approach is that you cannot obtain all of the current of each LDO and you will have a small voltage drop across the ballast resistors.  I have written new comprehensive collateral on this topic which you can read more about here:

https://www.ti.com/lit/wp/sbva100/sbva100.pdf

https://www.ti.com/lit/wp/sbva093/sbva093.pdf

Method 2: Op-Amp and sense resistors

You can add a very small series resistor in front of the LDO and using an op-amp, parallel the LDO's.  The method uses 1 LDO as the "primary" and all other LDO's as the "secondary".  This resolves the CON's of method 1, however the CON of this approach is that you need to ensure the new loop is stable.  We do not have the same level of depth in our collateral on this however you can get an idea of the method in this reference design. 

https://www.ti.com/lit/ug/tidu421/tidu421.pdf

Thanks,

Stephen