Other Parts Discussed in Thread: TPS2052B
I have a new PCB design that uses a TUSB4020BI to connect two devices to a computer. This is my first time using this part. I have a TPS2052B dual switch controlling power to both devices. Unfortunately, I can't get both switches in the TPS2052B to close at the same time. My schematic for this section of the circuit is below.
I can install either a pull up or pull down resistor on PWRCTL_POL. When I have a pull up, PWRCTL1 is high and PWRCTL2 goes low after ~5.5 seconds. Device manager says that there is an unknown USB device. When I have a pull down on PWRCTL_POL, PWRCTL1 is low and PWRCTL2 goes high after ~0.5 seconds. The device connected to DN2_VBUS shows up in device manager, and the device connected to DN1_VBUS does not show up. The signals coming out of PWRCTL1 (labeled EN1) and PWRCTL2 (labeled EN2) are shown below.
Since the overcurrent output from the switch is not getting triggered in either case, I can't figure out what is going on In other threads, it has been asked if the user had x rays of the soldering on the center pad (I do not). The board was hand assembled and reflowed in a modified toaster oven that has a controller to ramp the temperature along a reflow profile. I have used it plenty of times with good results, but if this behavior could be explained by poor solder coverage on the center pad I can believe that it could have happened.
Some other things that I have checked are the +1.1V_Hub measures at 1.09V, and +3.3V_HUB measures at 3.27V. GRSTZ is not being driven and is 3.27V. The crystal starts up and is 24MHz.
I am out of ideas and would appreciate any input. Thanks!
