The inverting and non-inverting configurations of the comparators form a window voltage detector circuit by using the internal resistor divider. The internal resistor divider allows for set voltage thresholds that already account for the tolerances of the resistors in the resistor divider. The UV and OV pins signal undervoltage and overvoltage conditions, respectively, on the SENSE pin, as shown in Figure 7-2.

Figure 7-2 Window Voltage Detector Schematic

The TPS3702-Q1 flags the overvoltage or undervoltage conditions with the most accuracy to make sure of proper system operation. The highest accuracy threshold voltages are V_IT–(UV) and V_IT+(OV), and correspond with the falling SENSE undervoltage flag and the rising SENSE overvoltage flag, respectively. These thresholds represent the accuracy when the monitored voltage changes from being within the desired window (when both the undervoltage and overvoltage outputs are high) to when the monitored voltage goes outside the desired window, indicating a fault condition. If the monitored voltage is outside of the valid window (V_SENSE is less than the undervoltage limit, V_IT–(UV), or greater than overvoltage limit, V_IT+(OV)), then the SENSE threshold voltages to enter into the valid window are V_IT+(UV) = V_IT–(UV) + V_HYS or V_IT–(OV) = V_IT+(OV) – V_HYS.