Hello,
We're encountering a serious issue with TUSB320HAI. It does not respond to any I2C commands from our STM32F whatsoever. We've scanned the entire address range, and it does not respond to anything. Other I2C devices on the bus respond correctly. I've attached the schematic and the layout. Note that R65 and R66 are not populated, therefore CC1 & CC2 lines are only controlled by TUSB320.
We've confirmed the following using an oscilloscope:
1. D3V3_STBY ramps up in under 2ms
2. I2C rise time is 120ns, fall time is 30ns. This is using 1K pull-up resistors
3. EN pin is low at start, and is pulled high by STM32F GPIO 300ms after power up.
4. ADDR pin is low.
5. No device is connected to USB port, therefore VUSBIN is floating.
6. No assembly issues. Device orientation is correct and is marked "HA".
7. Same observation on two different assembled units.
We did encounter the following anomalies:
1. Measuring PORT voltage, reads ~2.3V. We'd expect it to be 0V, given the pull down. We've confirmed that 1K pull-down is correctly connected.
2. Measuring VBUS_DET shows 0.5V, despite the fact that VUSBIN is floating/not connected
3. If EN is LOW then I2C pins read about 2.3V, instead of 3.3V!?
Any ideas?
Thanks in advance!
