TPS63061: Battery(VIN) loss condition

Kuramochi Tadahiko

Guru 28715 points

Part Number: TPS63061
Other Parts Discussed in Thread: TPS63031

Hi,

My customer is considering to use the TPS63061.

Input voltage is supplied by a battery, and a super capacitor is connected on output.

They connect the super capacitor to keep the output voltage when the battery is lost.

Follow is easy connection map.

When the battery is lost and output voltage is kept, is the TPS63061 occurs any problem?

Best Regards,

Kuramochi

over 8 years ago

0 Charles Wong1 over 8 years ago

TI__Intellectual 2270 points

what's the input voltage and output voltage/current for this application?

do you use 2cell super cap in series at the output voltage side?

from my experience a boost with bypass function is also a popular solution. but it depends on the applciation.

0 Kuramochi Tadahiko over 8 years ago in reply to Charles Wong1

Guru 28715 points

Charles-san,

Thank you for your quick response.

>what's the input voltage and output voltage/current for this application?

Input voltage is 8.4V(Li-INO 2cell), output voltage/current is 5V/0.5A.

>do you use 2cell super cap in series at the output voltage side?

I'm confirming.

Best Regards,
Kuramochi

0 Charles Wong1 over 8 years ago in reply to Kuramochi Tadahiko

TI__Intellectual 2270 points

if the input battery is 2 cell Li-ion that is 8.4V, the solution you mentioned above is correct, one cell super cap should <2.7V, the super cap will placed at the output side and a BUCK or buck-boost converter is needed. but buck is enough, as the input voltage should never<6V.

if the input battery is 1 cell Li-ion or li-ion battery in parallel, the solution should be a boost converter.

0 Kuramochi Tadahiko over 8 years ago in reply to Charles Wong1

Guru 28715 points

Charles-san,

Thank you for you help.

>do you use 2cell super cap in series at the output voltage side?
Yes.

When the battery is lost and output voltage is kept, the TPS63061 doesn't occurs any problem.
Is it correct?

Best Regards,
Kuramochi

0 Charles Wong1 over 8 years ago in reply to Kuramochi Tadahiko

TI__Intellectual 2270 points

yes sure, TPS63061 has load disconnect between VIN and VOUT.

0 Kuramochi Tadahiko over 8 years ago in reply to Charles Wong1

Guru 28715 points

Hi Charles-san,

Thank you for your help.

Load disconnect is works during shutdown.

Should we let the TPS63031 shutdown when battery is removed/installed?

Best Regards,
Kuramochi

0 Charles Wong1 over 8 years ago in reply to Kuramochi Tadahiko

TI__Intellectual 2270 points

I don't know whether TPS6306x has pull-down resistor on EN pin, but I'd recommend add one external.

0 Kuramochi Tadahiko over 8 years ago in reply to Charles Wong1

Guru 28715 points

Charles-san,

Thank you for your quick response.
However I cannot understand your answer.

I'm understanding that the TPS63061 should be shutdown during sudden battery removing/installing to enable load disconnect.
Is it correct?

Best Regards,
Kuramochi

0 Charles Wong1 over 8 years ago in reply to Kuramochi Tadahiko

TI__Intellectual 2270 points

what I mean is to add an external resistor(1M ) between EN and GND pin, It can help pull EN to GND when battery is removed, otherwise EN may be a high-Z node when battery is removed.

0 Kuramochi Tadahiko over 8 years ago in reply to Charles Wong1

Guru 28715 points

Hi Charles-san,

I'm sorry for delay and many time.

1. If battery is removed, must the TPS63061 be disable?
2. When battery is installed and output voltage is kept by super caps, can the TPS63061 occur a malfunction?

Best Regards,
Kuramochi

0 Kuramochi Tadahiko over 8 years ago in reply to Kuramochi Tadahiko

Guru 28715 points

Hi

How is this situation?

Best Regards,
Kuramochi

0 Juergen over 8 years ago in reply to Kuramochi Tadahiko

TI__Expert 5425 points

TPS63061 should not have problems when you remove the input voltage. If the EN pin is tied to the input voltage it should be ok as well.

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TPS63061: Battery(VIN) loss condition