SLVSFC5 November 2020 TPS552882
PRODUCTION DATA
The TPS552882 outputs a voltage at the CDC pin proportional to the sensed voltage across a output current sensing resistor between the ISP pin and the ISN pin. Equation 7 shows the exact voltage at the CDC pin related to the sensed output current.
To compensate the voltage drop across a cable from the terminal of the USB port to its powered device, the TPS552882 can lift its output voltage in proportion to the load current by placing a resistor between the CDC pin and AGND pin.
When using external output voltage feedback on the TPS552882, the output voltage rises in proportional to the current sourcing from the CDC pin through the resistor at the CDC pin. It is recommended to use 100-kΩ resistance for the up resistor of the resistor divider. Equation 8 shows the output voltage rise versus the sensed output current, resistance at the CDC pin, and the up resistor of the output voltage feedback resistor divider.
where
When RFB_UP is 100 kΩ, the output voltage rise versus the sensed output current and the resistor at the CDC pin is shown in Figure 7-6.