SNVSBJ0A December 2019 – June 2020 LM5170
To achieve the highest regulation accuracy over wider load range, the user should target to create 50-mV of VCS at full current. Therefore, RCS should be selected as Equation 47:
Ideally, a 1.5-mΩ current sense resistor should be chosen for this example. However, owing to availability, a standard non-inductive 1-mΩ current sense resistor is selected, namely,
Because RCS conducts the same current as the power inductor, its power dissipation is also determined by ILm_RMS.
If the selected RCS has parasitic inductance (assuming it is 1 nH), it should be compensated, and the compensation capacitor CCS should satisfy Equation 37.
Select the closest standard capacitor, CCS = 0.47 µF.
For optimal performance, it is good practice to add a 100-pF ceramic capacitor at each current sense pin to filter out common-mode noise, as shown in Figure 56.