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Fault in MIC29302UW(MIC29302UW is not giving correct output)

AMAN KUMAR

Dec 16, 2020
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Dec 16, 2020
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I am using MIC29302UW IC for converting 12V to 3.8V. I am using this IC from last 2 years and have used this LDO in more than 50 devices. But the same IC is not working in my new PCB board. I even made a small PCB, only for testing the working of MIC29302UW,but its not showing the correct output.


Let me explain the issue- I am providing 12V at the input of MIC29302UW and using 100k(R1) and 47.7(R2) resistors to form feedback loop. But instead of getting 3.8V(approx.), its showing 12V at the output pin. The input voltage is not stepping down from 12V to 3.8V.
So, what i can do to rectify this error and make it working? I have bought this LDO IC from DIGI-KEY. So, i am hoping that there is no fault in the IC.


NOTE: I am using the original MIC29302UW from DIGI-KEY.
 

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Harald Kapp

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As replied in your thread on All About Circuits, check the load current.
i am hoping that there is no fault in the IC.
If the chip fails to regulate even with proper load current, it is very likely defect.
 

AMAN KUMAR

Dec 16, 2020
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"If the chip fails to regulate even with proper load current, it is very likely defect."
---Do you mean i got the defective IC?
 

bertus

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Nov 8, 2019
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Hello,

The feedback resistors have a much to high value.
The minimum load for the MIC2930X is 7 mA:
MIC2930X_minimum load.png
What is your load current?
The package allows a smaller current:
MIC2930X_SOA.png
Bertus
 

AMAN KUMAR

Dec 16, 2020
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The problem was in led. The led was defective. I kept led at output. I changed the led and kept all the connection as i have mentioned in my question and now its working.
The issue was due to minimum load condition.
Thanks for your help and support
 
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