8.2.1.2 Detailed Design Procedure

Instead of being powered directly from the battery, the TLV7081 is powered directly from a voltage reference that exists in the system. The input to the comparator (IN) is allowed to operate above and below the reference voltage due to the unique analog front end of the TLV7081. When the battery voltage is above the reference threshold, the output of the comparator is high and when the battery drops below the threshold of the reference, the output of the comparator goes low (see Figure 22 for details). For simplicity, the integrated hysteresis of the comparator is not shown in the timing diagram. Integrated hysteresis is helpful in avoiding glitches at the comparator output when operating in noisy environments or when the input voltage changes thresholds very slowly. An open-drain output configuration allows the output logic level of the comparator to be level-shifted to match the logic level of the receiving device.