TPS7A47: Question about TIDA-01371

Hi Suzuki-san,

1 So these parts have much tighter tolerances on Vin, so if you were to use them you would have to make sure that your floating reference is able to rise high enough such that the absolute output of the LDO can get as high as you need it to be (Within 5V of Vin. This is why 7A47 was chosen as it is low noise, Wide Vin which allows a much wider tolerance on this value). If you are able t get the values within this tolerance, then it would work. Using these parts you do have a much higher 4A output, so if that current out is sufficient, then yes you would not need a current scaling to drive the application. But once again the potential problem with these parts is the much tighter Vin tolerance.

2 So if you utilize dual TPS7A47's, and their combined output is sufficient for the application, then yes you can use them in tandem. But in order to do this you need to utilize ballast resistors on their outputs to assure that you are load sharing, and not only sourcing from one while the other does not provide output.

Link for further understanding of ballast resistors

3 The important values are rating your input voltage sufficiently wide, and the output current your application needs, with current scaling this can give more leeway on the output current of the LDO, but it should still be kept in mind. That is the usefulness of the floating reference it allows higher inputs to be used on LDO operation. Additionally, you would like to keep noise low for clean signals for the possibly sensitive applications like ultrasound.