TPS7A80: tps7a80 vdo question in application

Dane Zhang

Part Number: TPS7A80

Hi team,

I see in E table the VDO=500mV(max) when Iout=1A;(VOUT + 0.5 V ≤ VIN ≤ 6.5 V, VIN ≥ 2.5 V, IOUT = 1 A, VFB = GND or VSNS = GND)

I have question:

if my application VIN has a accuracy of 3%. and VOUT has a accuracy of 3.92%.

when we set the VIN=5.5V; VOUT=4.984V

then we can calculate the actual difference between VIN and VOUT. Vin(Min)-Vout(Max)=5.5*(1-3%)-4.984*(1+3.92%)=155mV<500mV;

does that mean we can't use this VIN and VOUT because of the impact of the system accuracy? and we need to leave enough margin for the system accuracy?

over 3 years ago

0 Juliette over 3 years ago

TI__Genius 16596 points

Hi Dane,

We are looking into your question and will have a response by the end of the week.

Best,

Juliette

0 Mark Sellers over 3 years ago in reply to Juliette

TI__Expert 6825 points

Hi Diane,

Thanks for asking this question. If that is you input tolerance and output tolerance then you are correct that in the worst case you won't be able to use the device due to the deviations in the supplies. Can you provide your application requirements and we will get the best part for you to use?

Thanks,
Mark

0 Dane Zhang over 3 years ago in reply to Mark Sellers

TI__Expert 3420 points

Hi Sellers,

for TPS7A80 I still have a question:

I see in datasheet, the ABS table clarify the VOUT（MAX）=7V；

but in other LDO datasheet, the ABS MAX spec is often given as 7V/Vin+0.3V. I think it's because of the MOSFET's body diode.

So I want to know if TPS7A80 also require the VOUT<= VIN+0.3 ?

0 Mark Sellers over 3 years ago in reply to Dane Zhang

TI__Expert 6825 points

Hi Dane,

Yes that would apply here as well. You don't want to be forcing reverse current through the body diode. This can be avoided by putting a Schottky diode from Vout to Vin.

Regards,
Mark

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TPS7A80: tps7a80 vdo question in application