The TPS254900A-Q1 device integrates client mode as shown in Figure 8-6. The internal power switch is OFF to block current flow from OUT to IN, and the signal switches are ON. This mode can be used for software upgrades from the USB port.

Figure 8-6 Client-Mode Equivalent Circuit

Passing the IEC 61000-4-2 test for DP_IN and DM_IN requires connecting a discharge resistor to OUT during USB 2.0 high-speed enumeration. In client mode, because the power switch is OFF, OUT must be 5 V so that the device can work normally (usually powered by an external downstream USB port). If the OUT voltage is low, the communication may not work properly.