Hello,
We have developed a custom USB3 medical camera solution which required an intermediate board between the camera and the PC. First we tried a few different USB redrivers, with partial success. Then we switched to TUSB8020B, which works quite well and reliable except of very rare, intermittent, difficult to reproduce problems. The problems seem to appear at the start-up only, i.e., right after the hub (and a computer) is powered on: either the device (camera) connected to the hub is not detected properly, or it loses much of the data (image frames) sent later, or the camera stops streaming data entirely at some moment. The problems tend to persist until the hub is power-cycled, and disappear until one of the next power-ons, i.e., the entire system works perfectly, then it is powered off for a longer time (and kept intact), then powered on -- and sometimes it fails again.
We have found a mistake in our design with a too small capacitance which made the reset signal to be much shorter that the required 3 milliseconds, namely, 0.8 milliseconds at best. I know that this may be difficult to say how a chip behaves when it is used out of specs, but can this be a reason for such a strange behavior, as the unreliable operation described above (say, incomplete internal initialization of the chip resulting in distorted operation later)? The capacitance has been corrected in one of the boards which we have at hand (other boards are tested in the field), but due to the intermittent nature of the problem, we could not yet confirm whether it was a successful remedy.
Best regards,
Michal
