TPS63002 in parallel?

Ahmet Serbes

Other Parts Discussed in Thread: TPS63002, TPS63020, TPS63000

Hi all,

We need Li-Ion to 5V to power up our application and we have determined to use two TPS63002 in parallel to get 5V/2A peak. We have set up a board, in which outputs of the TPS63002s are simply short-circuited. However, one of the TPS63002 starts to warm up (and more input current is drawn) even if there is no load. By the way, they are performing pretty well when used independently (that is not in parallel). Is there a specific consideration when using two TPS63002 in parallel? Thanks in advance.

over 13 years ago

0 Darwin Fernandez over 13 years ago

TI__Mastermind 41790 points

Hi Ahmet,

Connecting two converters in parallel will result in uneven current sharing. One converter may operate in current limit while another may provide very little current. This application note explains how ballast resistors can be used to allow even current sharing.

http://www.ti.com/lit/an/slva250/slva250.pdf

Regards,

Darwin

0 Chris Glaser over 13 years ago

TI__Guru**** 150950 points

Another option is to use the higher current, TPS63020 device.

0 Ahmet Serbes over 13 years ago in reply to Darwin Fernandez

Prodigy 90 points

Hi Darwin,

Thanks for your help. I will definitely use appropriate ballasting resistors in the final design.

Of curiosity, why is it heating up in a no load condition? Is it normal?

Thanks.

0 Darwin Fernandez over 13 years ago in reply to Ahmet Serbes

TI__Mastermind 41790 points

Ahmet,

It may be that because one of the converters has a slightly lower voltage than the other, that current may be flowing from one converter to the other. Using ballast resistors would separate these different regulated voltages and fix that problem.

Regards,

Darwin

0 Mario Hernandez over 10 years ago in reply to Darwin Fernandez

Intellectual 695 points

Hi Darwin,

It's been a while but I got two questions on this topic:

Using ballast resistor would not lower the output of the DCDC?

Would I experience the same effect if I parallel a DCDC and an LDO?

Many thanks

0 Chris Glaser over 10 years ago in reply to Mario Hernandez

TI__Guru**** 150950 points

I split your other thread since you have a new question that is not about paralleling two TPS63000 devices. Here it is: http://e2e.ti.com/support/power_management/non-isolated_dcdc/f/196/t/380104.aspx

Yes, the ballast resistor approach does create some change in the output voltage as the load current varies.

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TPS63002 in parallel?