LM2731: LM2731XMF/NOPB

Luis Suarez

Part Number: LM2731

Hello everyone,

I was wondering if the LM2731XMF/NOPB can output a voltage higher than the 20V max if I reference ground to a higher voltage. Let's say I have 50V at Vin and a ground reference of 40V, would the device the the input as the differential (50-40 = 10V) and boost the voltage to 60V (20V above the ground reference 40V) or does it not work this way? I try simulating it and when I feed an input higher than 20V it will not boost but instead outputs what I have feeding the input. Please see below the configuration I have:

I would greatly appreciate your help.

over 2 years ago

+1 Zack Liu over 2 years ago

TI__Mastermind 34201 points

Hi Louis,

Theoretically I think your idea has no problem. The only difference is reference GND pin is changed from 0V to 40V.

In the simulation, lots of components in the internal circuit already connects to GND so you cannot get the result that you want.

0 Luis Suarez over 2 years ago in reply to Zack Liu

Prodigy 50 points

Hi Zack,

Thank you so much for your quick response. So my idea should work in practice, correct? Just want to make sure.

0 Zack Liu over 2 years ago in reply to Luis Suarez

TI__Mastermind 34201 points

Hi Luis,

I never tried designing a circuit like that. But I think it should be OK theoretically.

0 Luis Suarez over 2 years ago in reply to Zack Liu

Prodigy 50 points

Thanks Zack.

I will build the circuit to test the theory. I can let you know if it works if you would like to know.

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LM2731: LM2731XMF/NOPB