This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
I am sorry to insist but I would like to check on this:
The reazon why I want to use 2 LDOs in parallel configuration it is not to increase the current. It's is a safety issue.
My idea is to connect in parallel two NMOS LDOs TPS73633 with different battery input. If any battery fails, the regulated output should be fine because the other battery input is still working. No current will flow back to the broken battery because the LDOs are NMOS.
Moreover, the load current is 1/2 of the output current of a single LDO, so in case the current is not balanced, the LDO that has to deliver all the current is able to do it.
Do you see any problem in this configuration?
Thanks a lot in advance.
If load sharing of more than the rated current of TPS73633 is not an issue, such as your application, then I do not see a problem with your configuration.
In reply to Darwin Fernandez:
Thanks a lot for the answer.
Is there any app note about the different kinds of LDOs failure modes: short circuit, open circuit....
In reply to Nuba:
Unfortunately, we do not have application notes for this. Typically, if there is internal protection (current, thermal) that takes the output voltage out of regulation but does damage the part. However, from what I have seen, MOSFETS usually damage into a short circuit. If the output of the LDO just follows the input without regulating, the LDO is probably damaged.
Thanks for the answer.
So, if i understood you right, from what you have seen, MOSFETS damage in shortcircuit. So Input and Output are connected together and i will see at the output the input voltage. Is this what you meant?
Is there any failure mode that a LDO can present a shortcircuit to GND at the output? This case would be more dangerours to me since i have two LDO in parallel.
Thanks in advance.
Yes, anytime I notice the output following the input all the way to the maximum input rating, the IC is probably damaged.
Fortunately, the TPS73633 has short circuit protection and limits the output current of the device to 450mA when the output goes below 0.5V. See page 13 of the datasheet.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.