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TPS74801: TPS74801 dropout mode

Part Number: TPS74801
Other Parts Discussed in Thread: TPS7A10

Hi Expert,

For some reasons, Customer uses TPS74801 in Dropout mode(Vbias <Vout+1.6V) and wants to know if it can work for a long time.

Could you help to check and give some comments to customer's questions? Thanks.


1. Dropout Voltage near 800mV more detailed current curve or data.


2. provide some detail reliability test data( red items)

  • Hi Oliver,

    I would not expect the reliability of the component to change if it were operating in dropout, as the reliability is often based on operating at 55C.  Operating in dropout at these current levels will not raise the device temperature very much.  The quality information for this component is location in the product folder here:

    For example, clicking on the first item gives the following qualification summary:

    I checked the datasheet and the archives, but for this 13 year old device I cannot locate data describing the load current vs dropout less than 800 mV.  In my opinion it does not look like the customer is using the right device if they need a headroom less than 800 mV and they are drawing very light current.  We probably have a much better LDO for the customer if they can offer their requirements to us (Vin, Vout, Iout, and anything else they think we should know).

    I would recommend the TPS7A10 which can stay out of dropout voltage with Vin = Vbias up to about 210 mA load current across temperature.  The plot below is from the TPS7A10 datasheet.


    - Stephen