High power linear regulator circuit using TPS7A4701

Hi,

From the Circuit that you have given us there is not enough information to tell you if the TPS7A47 will work in this application. It would be helpful if you would be able to provide us with some more information.
Would you be able to provide the following information:
1) Input Voltage to the TPS7A47.
2) Required Output Voltage of the Regulator.
3) The amount of outuput current expected.
4) The values of the Feedback resistors RA7,RA8.

Best Regards,
Mark

Hello Mark,

Input voltage is 24V and output voltage is 22V. Current rating is 3A max.

Front end of this input side is 24V transformer ... So it is linear high power regulator for audio power.

Regarding PCB layout, it was not done....

Our customer is asking us which is better , this kind of circuit with external TR or Parrelel tied of two or three TPS7A47 for higher current use...

I would like to have your advice....since the customer was very satified with output ripple spec of TPS7A47 except current rating.. 

Thanks and best regards,

Hi,

I have attached another e2e post where they are discussing the use of external pass devices to take some of the current load off of the LDO. This post also covers the TI Design which goes over using multiple LDOs in parallel to implement current sharing. 

http://e2e.ti.com/support/power_management/linear_regulators/f/321/p/474348/1705789#1705789

As we have never tried using external BJT's as pass devices I do not know what kind of output ripple and noise can be expected from that design, but the current sharing design shows that using multiple LDO's will keep the output noise down.

Let me know if you have any other questions.

Best Regards,

Mark

Hello Mark,

This is really good information,, Thanks a lot...

I am thinking this circuit for the requirements. However, I don't have idea on this resistance value on red highlighted...Would you advise me these values?

Thanks and best regards,