SLUSCD4B March 2017 – May 2018 TPS543C20
RSP and RSN pins are used for remote sensing purpose. In the case where feedback resistors are required for output voltage programming, the RSP pin should be connected to the mid-point of the resistor divider and the RSN pin should always be connected to the load return.
In the case where feedback resistors are not required as when the VSEL programs the output voltage set point, the RSP pin should be connected to the positive sensing point of the load and the RSN pin should always be connected to the load return. RSP and RSN pins are extremely high-impedance input terminals of the true differential remote sense amplifier. The feedback resistor divider should use resistor values much less than 100 kΩ. A simple rule of thumb is to use a 10-kΩ lower divider resistor and then size the upper resistor to achieve the desired ratio.