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REF3325: REF3325 minimum dropout voltage.

Part Number: REF3325

Hi team,

My customer met a problem about the REF3325. In our datasheet, the minimum Vin is listed as below:

My question is:

1. What's the difference between the "specified voltage range" and the "operating voltage range". Why the minimum Vin is different?

2. In my customer's case, the Vin of REF3325 is 2.5V and the load current of the REF3325 is 1mA. Customer tested several boards and the REF3325 can output 2.5V. But they wonder is this a reliable condition to generate a 2.5V reference from a 2.5V Vin with 1mA load?

Best regards,


  • Hi Wayne,

    1. The operating voltage range is under the condition that ILoad = 0mA so there is no dropout voltage. Once there is a load, there is a need for a dropout voltage for proper regulation. This dropout voltage can be seen in Fig 4. The "+0.2V" takes into account any load current from 0mA to 5mA for proper regulation.

    2. Figure 4 is a typical graph that shows dropout vs ILoad. While your customer is able to provide 2.5V with a 1mA ILoad and get a 2.5V regulated output, that voltage range is outside of the recommended operating condition and therefore outside of what we can guarantee for the EC table. The device might be working marginally and not as accurately as it could be working. While this might work for some devices, it might not work for all devices and variations.

    -Marcoo Z