The resistor divider values and target threshold voltage can be calculated by using Equation 1 to determine V_MON(UV).

Equation 1.

where

• R1 and R2 are the resistor values for the resistor divider on the SENSE pin
• V_MON(UV) is the target voltage at which an undervoltage condition is detected

Choose an R_TOTAL ( = R1 + R2) so that the current through the divider is approximately 100 times higher than the input current at the SENSE pin. Use resistors with high values to minimize current consumption (as a result of low input bias current) without adding significant error to the resistive divider. For details on sizing input resistors, refer to application report SLVA450, Optimizing Resistor Dividers at a Comparator Input, available for download from www.ti.com.