Hi E2E team.
This is Jonathan from Avnet.
One of our customers, applied TUSB215 to CAR-Amp system in order to compensate for signal loss in a transmission channel.
Nowadays, they are working on USB Device/Host interoperability test with different kinds of smart-phone such as Apple & Android.
There have been fewer problems with most of the smart-phone model regardless of Device/Host mode.
But it doesn't work with particular smart-phone model such as “Nexus 5X” when smart-phone is set to Host mode for USB interface.
The results so far show that the problem occurs when LPC1825(Application Processor) is set to USB-Device mode and “Nexus 5X” is set to USB-Host mode.
In case of abnormal operation, TUSB215 VREG port is toggling high and low over and over.
Please review test environment and USB & VREG wave-form below, and then let me know the cause of trouble.
Thanks.
1. Test environment.
2. Application schematic.
3. Abnormal & Normal USB Signal Waveform (VBUS, USB D+, UDB D-, VREG)
- Abnormal Case with Nexus 5X
- Normal Case other smart-phone except Nexus 5X
