TPS63900: Supercap charging

Viktor Schneigelberger

Part Number: TPS63900

Tool/software:

Hi,

In a battery powered meter application the TPS63900 shall recharge the voltage on a supercap as soon as the voltage drops below 3.6V (so the boost should recharge from 2.5V up to 3.6V).

At the initial instant when the supercap is charged at 3.8V while the battery is at 3.6V, can it be confirmed that TPS63900 blocks any current circulation to the battery?
As soon as the voltage on the supercap drops below 3.6V, the boost starts charging the supercap instead, right?

Regards,

Viktor

6 months ago

0 Shipeng Cheng 6 months ago

TI__Genius 17000 points

Hi,

We will reply after weekend. Thanks.

+1 Tao Zhang 6 months ago

TI__Mastermind 32350 points

Hi Viktor,

I am curious why supercap will be charged to 3.8V, the target is 3.6V, right? Your understanding is correct, once Vout of TPS63900 is higher than it's target, device change operation mode to PFM automaticlly, which means there will be no reverse current from Vout to Vin.

Also, once Vout of TPS63900 is lower than target, device will start to charge the supercap again.

Regards

Tao

0 Viktor Schneigelberger 5 months ago in reply to Tao Zhang

TI__Intellectual 1030 points

Hi Tao,

I marked the thread as solved but I would like to double check since I cannot find the details in the datasheet.

The target is 3.6V. So in the initial instance when the super cap is charged to 3.6V and the battery is charged to 3.6V there is no need to insert any protection diodes between battery and supercap as the TPS63900 blocks the reverse current flow from supercap to battery?

Regards,

Viktor

0 Tao Zhang 5 months ago in reply to Viktor Schneigelberger

TI__Mastermind 32350 points

Hi Viktor,

Yes, no additional protection needed to avoid reverse current from supercap to battery.

Regard

Tao

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TPS63900: Supercap charging