8.2.2.10 Minimum V_IN

To ensure proper operation of the device and to keep the output voltage in regulation, the input voltage at the device must be above the value calculated with Equation 43. Using the typical values for the R_HS, R_DC and V_F in this application example, the minimum input voltage is 5.56 V. The BOOT-SW = 3 V curve in Figure 1 was used for R_DS(on) = 0.12 Ω because the device operates with low drop out. When operating with low dropout, the BOOT-SW voltage is regulated at a lower voltage because the BOOT-SW capacitor is not refreshed every switching cycle. In the final application, the values of R_DS(on), R_dc and V_F used in this equation must include tolerance of the component specifications and the variation of these specifications at their maximum operating temperature in the application.

Equation 43.