STUSB1600 can't work as source

[Gerald_W]

Dear All,

 

Hello everyone, I used STUSB1600 as the type-c dual role type power management. When it works as sink type, it is good. But when it works as source type, it doesn't work. I found VBUS_EN_SRC always keep high. This is my design schematic, could you please provide some suggestions. Thank you so much!

 

Best wishes,

Gerald.

[Richard Li]

Is CCxDB pin1,5 cause problem?

If you don't need dead battery function, you may connect these pins to GND.

[Gerald_W]

Hi Richard,

Thanks for your replying. My system is powered by a 3.7v Li battery. I think I need to use the dead battery function. I am also considering VSYS cause the problem. Maybe I should connect VSYS to 5V or VBAT, not GND (in the schematic I am testing, I connected VSYS to GND, sorry for the confusion).

 

Best regards,

Gerald

[Richard Li]

Hi, Gerald,

For my experience, every power chip vsys use for inside engine, if no power, totally no function, your sink shouldn't work.

Even you need dead battery function, you may connect one 33K resistor between cc-ccxdb pins to GND, avoid noise cause problem ( outside device no cc pin control.)

(33K only cause 0.1mA current when signal high)

Regards,

Richard Li

[NBALL]

Hello

Could it be possible, please, to share oscilloscope waveforms of vbus-CC1-CC2-vbus_en_src ?
I'd like to see the behavior when sink is connected to your PCB (i.e when stusb1600 acts as source)

Thanks

Nathalie 

[Gerald_W]

Hello Nathalie,
Thanks for your replying. I did some rough measurement and found VBUS to be 0v, CC1 and CC2 to be 0v, and vbus_en_src to be 5v. I will provide detailed waveforms later today.

 

Thanks,

Gerald

 

 

[NBALL]

Hello Gerald

As stusb1600 is in DRP configuration, without any cable connected, I do expect to see CC toggling between ~3V and 0v

By default, Rp is setup to advise 3A so when Sink is connected, I expect to see 1 CC pin at ~1.6V. 

If CC are zero when connected to sink, it means that stusb1600 is in ErrorRecovery state (it has disabled its resistors): most probably, the device detects wrong voltage on power paths.
VDD pin should be connected between U8 and U9 from your schematic: see fig 10 of our datasheet.
Best regards
Nathalie