TPS2120: Super Cap Power Mangement - Part Suggestion

Dinesh Amara

Part Number: TPS2120
Other Parts Discussed in Thread: TPS25948, TPS25947

Tool/software:

I would like your expertise part suggestion for the following application.

The main body with controller electronics are driven by a detachable power handle which has a 7.2V 2s1p battery pack along with fuel gauge and charger circuitry. The user has to change the existing handle with spare power handle when the battery runs out. During the power handle swap say 30seconds, I would like the super caps to take over from power handle batteries so the main controller stays On all the time.

Could you recommend the appropriate controller (hot swap controller? or Power Mux switch TPS2120?) which can be used for the above application.

Operating voltage 7.2v to 8V

Idle Current - <10mA (During swap the controller will be in idle mode)

maximum operating current 2A.

During the power handle swap, the hot swap controller must be powered on from the super caps as well.

let me know if you need more information regarding my application.

Kind Regards

over 1 year ago

0 Kunal Goel over 1 year ago

TI__Guru* 79181 points

Hi,

Let me check and get back on this.

Regards

Kunal Goel

0 Kunal Goel over 1 year ago in reply to Kunal Goel

TI__Guru* 79181 points

Hi DA,

TPS2120 can be a good fit.

You can also check eFuse device TPS25947, TPS25948. They offer power muxing.

Regards

Kunal Goel

0 Dinesh Amara over 1 year ago in reply to Kunal Goel

Prodigy 20 points

Thanks for the confirmation :)

Do you any reference designs from TI, I could adapt? TIA

0 Kunal Goel over 1 year ago in reply to Dinesh Amara

TI__Guru* 79181 points

You can check product page . It might have some links.

Regards

Kunal Goel

0 Dinesh Amara 11 months ago in reply to Kunal Goel

Prodigy 20 points

Hi Kunal I have checked the efuse's

TPS259541DSGR and i feel this is a good fit for the above application. Could you please confirm? Ideally the Input to

is from a 7.2V battery and Output is connected to 1F super cap with RLIM set to 1A and 3.3nF Cdvdt?

Please find the attached block diagram and let me know your comments or suggestions.

0 Kunal Goel 11 months ago in reply to Dinesh Amara

TI__Guru* 79181 points

Hi Dinesh,

I will check and get back on this.

Regards

Kunal Goel

0 Dinesh Amara 11 months ago in reply to Kunal Goel

Prodigy 20 points

Hi Kunal

Check the attached schematic and let me know if this works ok? 1F super cap (Charge time 13.2s @0.55A and Vout is connected to Load and is around 2A), I have set the ILIM to 2.7A. Let me know if I need to make any changes or changes to resistor values.

Kind Regards

0 Dinesh Amara 11 months ago in reply to Dinesh Amara

Prodigy 20 points

HI Kunal

Any update on this? The above values are based on the following conditions

Input - 7.2V
UV Threshold - 5.02V
OV Threshold - 8.61V
Max Load Current - 2.7A
Super Cap - 1F
Charge Time - 13.2S @0.55A

Also, the ILIM 0.55A is used to charge the supercap as backup power supply, what would be the case if my load is 1.5/2A? should i need to set ILIM to load levels?? because Vout power up the load which can take up to 1.5A.

Kind Regards

0 Arush Gupta 11 months ago in reply to Dinesh Amara

TI__Mastermind 38985 points

Hi Dinesh,

I am ooo this week. I will provide you with the feedback by Tuesday next week.

Thank you for understanding,
Arush

0 Arush Gupta 11 months ago in reply to Arush Gupta

TI__Mastermind 38985 points

Hi DA,

These settings look fine but most likely the device won't be able to provide this high inrush current and will need multiple restarts to charge the output capacitor. Here is one app note on this. https://www.ti.com/lit/pdf/slva920#:~:text=While%20charging%20the%20super%20capacitor,power%20dissipated%20decreases%20as%20well.

Dinesh Amara said:
Also, the ILIM 0.55A is used to charge the supercap as backup power supply, what would be the case if my load is 1.5/2A? should i need to set ILIM to load levels?? because Vout power up the load which can take up to 1.5A.

ILIM limit is set based on your system maximum current load + some buffer. During regular operation, you need 1.5A current so set ILIM more than that.

Best Regards,
Arush

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TPS2120: Super Cap Power Mangement - Part Suggestion