IC for limit voltage to 5.1 V max

Roque Belda

Other Parts Discussed in Thread: BQ25570, TPS62050

Hi, I tell you my problem. I'm going to use the BQ25570, it only supports a maximum of 5.1 V in Vin, and my solar panel is 6 V. I would like to limit this voltage with some low power IC (like TPSXXXX), but I do not want to set the output voltage to 5 V, only limit the maximum. Can anyone recommend me some IC?

over 6 years ago

0 Raheem over 6 years ago

TI__Mastermind 21590 points

Hi,
Please take a look at the TPS62050 here: www.ti.com/.../tps62050
-Raheem

0 Christian Grau28 over 6 years ago in reply to Raheem

Intellectual 375 points

Dear Raheem

Thanks for your Support. I have about the same Problem. My solar cell can provide about 8V and I saw, that the BQ25570 Claims to protect itselfs, if the source had at least 20Ohm impedance.
I wonder why the datasheet does not specify a Maximum current it could potentially sink, since the source voltage is not known.

Could you please explain how the switcher is supposed to help in case of over-voltage? Does it just dump the excess power to a load? Why use a switcher in that Situation?

Many thanks and Kind regards

Chris

0 Raheem over 6 years ago in reply to Christian Grau28

TI__Mastermind 21590 points

Hi,
The absolute max input voltage for this device is 5.5V. Any voltage above that could potentially destroy the IC. The maximum input power for the IC is 510mW. A buck converter can be added before the Energy Harvester to lower the input voltage.
Regards,
Raheem

0 Christian Grau28 over 6 years ago in reply to Raheem

Intellectual 375 points

Raheem

Thanks for the Explanation. By adding a Switcher one will loose the cool energy harvesting capabilites of BQ25570. TPS62050 will take at least Vgs_th of the Power PMOS at its input to become conductive. Isn't that hindering the cold start mechanism of the BQ?

Is there some other Input clamping mechanism that does not consume several uA?

Regards

Chris

0 Christian Grau28 over 6 years ago in reply to Christian Grau28

Intellectual 375 points

Raheem

I think I got it now... If I have a solar cell, that can provide more than 500mW then I probably don't neet to harvest a few uW.

Thank you for your Patience and Kind regards

Chris

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IC for limit voltage to 5.1 V max