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ATL431LI: TL431LI as a replacement for TLV431a

Part Number: ATL431LI
Other Parts Discussed in Thread: TLV3502, , TLV431A, TL431, TLV431, ATL431


I currently use the TLV431A to generate a reference voltage of 3.225 for the TLV3502 component, from a voltage of 3.3V using the circuit described in the attached TINA simulation. Since I have a space problem in the my PCB, I would like to use the ATL431LI component. I want to make sure that using this component will give me, with changing the resistors as described in the attached simulation , the same result.


Yossy Goldenberg


  • Hello Yossy,

    I would suggest redesigning your circuit. The TLV / ATL431 wasn't meant to be used in this configuration. I suggest using a circuit layout like this for the ATL431LI. There should be an input resistor on the cathode like R5.

    Also I would suggest prototyping and testing this circuit physically as regulating from 3.3V to 3.225V is very close together in voltage without much margin. Your resistor tolerances might need to be very high. Power supply variation and current draw will affect the output. 



  • Hello Walter,

    Thank you very much for your reply and comments!

    This circuit has been working for the last 12 years, and we have not encountered any special problems. I'll check out the R5 resistor you suggested, it might improve the system's reliability, but it might take me away from the reference voltage I need.

    I'm designing a very small PCB, so I thought of using the ATL431LI, but I agree with you about the margin, which may increase the problem of using a 2.5V reference that didn't cause an actual problem with1.24V reference.

    I will use one of the most important rules in planning  "if it works don't touch".Grinning


    Yossy Goldenberg