TUSB320: USB-C Charger Design based on TUSB320

Kaveh Mohammad

Part Number: TUSB320
Other Parts Discussed in Thread: BQ25170

Hi,

I have designed a battery charger based on BQ25170DSGR and want to charge my battery in CC-CV mode with 40mA current limit and 4.1V voltage limit.

The interface with outside is a USB-C. It is expected that USB-C provide 5V DC on VBUS lines for BQ25170DSGR chip in the charger.

How can my charger operate with any 5V-3A USB-C charger? Do I have to use TUSB320 as an interface between my USB-C port and BQ25170DSGR chip? Do I have to include power negotiation? Is there an example implementation that would help me in this case? Can I simply communicate with an external charger to put 5V DC on VBUS lines only by adding pull up or pull down resistors on CC1 and CC2 lines.

Thanks

over 3 years ago

0 Brian Zhou over 3 years ago

TI__Guru**** 161736 points

For CC port, you do need either CC controller or PD controller for lots of CC communication. It will decide either it's DFP , uFP or URP mode, when to turn on Vbus and what current mode is.

Regards

Brian

0 Kaveh Mohammad over 3 years ago in reply to Brian Zhou

Intellectual 585 points

Thanks Brian,

There is no data communication or better said I dont need to communicate any data over data lines. My charger is UFP sink USB 2.0 and just requires 5V DC on the bus (Current < 50mA) as its power supply.

So for a simple design like this I still need to use a USB-C controller like TUSB320?

0 Brian Zhou over 3 years ago in reply to Kaveh Mohammad

TI__Guru**** 161736 points

even if no USB data, still need cc controller like TUSB320 to configure as UFP.

Regards

Brian

0 Kaveh Mohammad over 3 years ago in reply to Brian Zhou

Intellectual 585 points

I have a USB-C charger that can provide 5V-2A or 9V-1.67A as written on the its body. When I connect that to my system, it provides 5V on VBUS lines that I want without having a USB-C controller or having any of the other pins such as D+/D- and CC1/CC2 connected to anything.

0 Kaveh Mohammad over 3 years ago in reply to Brian Zhou

Intellectual 585 points

If we do not use a controller, is it non-compliance with USB-C standard?

0 Brian Zhou over 3 years ago in reply to Kaveh Mohammad

TI__Guru**** 161736 points

If you can get 5v form USB-C charger , then you may not need CC controller.

can you draw a block diagram.

Regards

Brian

0 Kaveh Mohammad over 3 years ago in reply to Brian Zhou

Intellectual 585 points

It is very simple. I just get 5V from VBUS on USB-C to supply BQ25170.

0 Brian Zhou over 3 years ago in reply to Kaveh Mohammad

TI__Guru**** 161736 points

Maybe the USB-C charger is DFP and Vbus is out all the time.

Regards

Brian

0 Kaveh Mohammad over 3 years ago in reply to Brian Zhou

Intellectual 585 points

Thanks Brian. So if I connect my BQ25170 charger design above to a USB-C device that can take DRP role then that device may not put 5V on the bus because I dont have a USB-C controller on my BQ charger?

I am trying to justify using a USB-C controller in my design and see if I use it or not to what type of USB-C devices I can connect my BQ charger to get 5V supply from it.

I hope I explained it properly. If this is irrelevant to this forum I appreciate if you refer me to where this would be relevant.

0 Brian Zhou over 3 years ago in reply to Kaveh Mohammad

TI__Guru**** 161736 points

If BQ25170 charger connected DRP, DRP should send out 5v untill successfully configured as DFP. Since there is no CC commnication, DRP will keep in DRP mode and never send out 5V.

So you do need CC controller.

Regards

Brian

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TUSB320: USB-C Charger Design based on TUSB320