HD3SS3220: ID Pin never goes low

Hi,

1. The pullup on ID is rather strong. You should use a 200K pullup resistor, not a 4.75K pullup.

2. Does VBUS ever get enabled while our ID pin is high?

3. You have the HD3SS3220 in I2C mode based on the ADDR pin. What writes are you making to the device?

Is this the same design discussed in this E2E post? I can resolve that post if you'd like to use this thread instead.

Best,

Shane

Shane,

1.  Changed the pullup to 200K.  The ID pin still never goes low.

2. USB01-VBUS goes high after reset and stays high.

3.  This might be an issue.  The designer expected the power on reset state to be DRP.  Currently we are not using the I2C bus.

It is the same design discussed in the post you highlighted.

Without anything plugged in CC1 and CC2 are both low.  Should there be periods of high for DRP?

I tried plugging into a PC as a host machine, treating the design as an UFP.

CC1 was at 1.7V and CC2 was at 0V

Flipping the USB-C connector resulted in:

CC1 at 0V and CC2 at 1.7V

THANKS

Jeff

Hi Jeff,

first_name Grant said:

Without anything plugged in CC1 and CC2 are both low.  Should there be periods of high for DRP?

Yes, when the HD3SS3220 is configured for DRP you should see the CC1/2 lines alternate between 0V and 5V. By default, the HD3SS3220 will set the role based on the PORT pin, even in I2C mode. Since you have PORT as NC, this should operate as a DRP.

When nothing is plugged in:

• VDD5 should be 5V
• ENn_CC should be pulled/driven low
• The Type-C VBUS should be low
• CC1/2 should alternate between 0 and 5V (DRP)

Can you check whether the VBUS and ENn_CC voltages are correct in the unattached state?

Best,

Shane