Li-Po Single Cell Charger - USB-C Power Delivery

Hi All.

I am doing a project which is a Li-Po (Single Cell, 6000mA) Powered ARM CPU based device. It have USB-C receptacle and SD Card. The CPU have USB 2.0 and USB 3.0 both in OTG. This device mainly feature:

-# File transfer between PC (USB 2.0 or 3.0) and Board's SD card (USB Device Mode)
-# File transfer between SD card (USB 2.0 or 3.0) and any USB 2.0 or 3.0 Storage Device like Portable HDD/SSD or PenDrive etc (USB Host Mode)
-# Charge the Board Li-Po via USB-C 5V, 3A (15W)

My ques is mainly on the Charging circuit. For my application do I need to implement USB-C Power Delivery circuit to enable the Li-Po charging from a USB-C PD Charger? If a non PD system connects to a PD Charger or MacBok Pro then can it get 5V 3A by default without PD negotiation?

Thanks in advance.

Regards.

Isn't the purpose of enumeration to stop a short circuit, or to prevent drawing such extreme current that it could break circuitry inside valuable equipment?
It's a safeguard so it seems risky to bypass it.

Hi BradtheRad. Thanks for reply. Yes, I agree, need protection circuit. better to use dedicated USB-C Controller.

But do I need to use a PD Controller Chip? Or only CC Controller will be Ok for my case.

To my understanding as my Device have Single Cell Battery and to charge it needs 5V ... which by default comes from a PD Charger (5V, 3A)?

Regards.

In regard to modern USB protocols I believe your knowledge is greater than mine. I understand a USB port provides 130 mA by default, until the peripheral does the enumeration routine. Otherwise the computer gives an error message: "Your device tries to draw more power than the USB port can provide." Twelve years ago new external USB drives needed two separate cables to hook up to my laptop. One cable for data, one for power.