External Current Limiting Circuit Recommendation for STUSB1600

[TIENHUA]

Hi Sir,

I am reviewing the application schematic of the STUSB1600 in a dual-role Type-C design. I understand that when STUSB1600 operates as a Source, the output current can be configured through the CC_CAPABILITY_CTRL register.

However, I did not see an explicit current limiting component in the provided schematic. I would like to ask whether ST has any recommended external circuit solutions to further enforce current limitation, such as a preferred power switch or current limiting IC that is compatible with this setup.

Additionally, I would like to confirm: if we only configure the CC_CAPABILITY_CTRL register without any external current limiting components, would the actual output current still exceed the configured 1.5A limit in certain conditions? If so, could you provide a reference circuit diagram or recommendations for suitable current limiting components that ensure proper current regulation?

[Peter BENSCH]

Unfortunately, you have misunderstood the abbreviation CC - it does not stand for Constant Current, but for Configuration Channel.

According to the data sheet, section 5.1.10, byte CC_CAPABILITY_CTRL at address 0x18 is used for:

When operating in source power role, this register allows the advertising of the current capability to be changed as defined in the USB Type-C standard specification and the VCONN supply capability.

The exact meaning of the individual parts of this byte can be found directly below in table 26 of the data sheet.

Does this answer your question?

Regards
/Peter