I tested the TL431IPK at the company and found that the voltage is usually between 2.486 and 2.489. After the user received the product, there was an abnormality and it was returned. The measured TL431IPK reference voltages were 2.501V and 2.509V, respectively. After replacing the new IC, the voltage was normal. May I ask what is the reason for this? Are there any measures to avoid this situation?
Hello,
For TL431IPK, the voltage tolerance at 25°C is seen below:
So 2.486V is within datasheet specification. So is 2.509V.
If you would like a tighter accuracy specification of 1% at room temperature please consider TL431AIPK:
Or you could consider TL431BIPK for the highest accuracy grade of 0.5%:
Also keep in mind that if the temperature changes, you must also take into account the deviation of reference input voltage over full temperature range, which is also noted for each accuracy grade in the datasheet.
If you want accuracy better than 0.5%, please consider a series voltage reference such as REF3025AIDBZR or REF35250QDBVR.
Thanks,
