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Hi,
Can you share the test procedure/testsetup for validating the Reverse leakage current, internal reference and output noise voltage of an LDO in bench testing.
Regards
Anuraj NK
Thanks Mark for your quick replay.Now I can prepare the test procedure for reverse leakage current and Noise testing with reference to your above mail.Can you tell me the procedure for validating the internal reference voltage for adjustable LDO, which you missed to address in the previous mail.
Hi Mark,
I understood the method for fixed regulator. I am confused with your answer for adjustable regulator. I am not interested to check the value of internal feedback when the output is stable. My requirement is to validate the FB pin voltage range (as mentioned in datasheet) to make the output stable. It is for IC validation purpose.
Regards
Anuraj NK
Hi Anuraj NK,
Would you be able to give some more detail about what you are trying to test?
Are you talking about the line listed in the electrical characteristics table? If so the easiest way to test this will be to put the LDO is unity gain and measure the output voltage of the LDO using the test conditions listed in the datasheet.
The LDO uses an amplifier to assist in regulating the output voltage. One input terminal to the amplifier is the internal reference to the LDO the other is the FB node, when the LDO is regulating the output voltage the two nodes should be equal to each other. When the LDO is regulating the output voltage the FB voltage should be equal to the reference voltage. If the LDO is in dropout the FB voltage will be less than the reference voltage. And if the output is greater than the target voltage the pass FET will be off and and FB voltage will be greater than the reference voltage.
Best Regards,
Mark
Hi Mark,
Yes, I am trying to validate the line listed in the electrical characteristics table.
Configuring the LDO to unity gain is using the transformer by inject an AC signal into the feedback path between points "A" and "B" as shown below or any other procedure is available. Please let me know.
Regards
Anuraj NK
Hi Mark,
Connect the LDO as per below config. Measure the output voltage and verify that the output is with in the range of internal feedback reference mentioned in the electric characteristics of datasheet ( Between 1.198V - 1.210V) Is that you mean for validating internal voltage refernce.Please confirm.
Regards
Anuraj NK