The TXS03121 is a comparator designed for battery monitoring applications. It can be operated with a voltage of 2.5 V to 5.5 V. The reference voltage is applied to the –IN terminal, whereas the voltage to be monitored is connected to +IN. When the voltage at +IN is greater than the voltage at –IN, the output FET is turned On. When the voltage at +IN is less than the voltage at –IN, the output FET is turned Off. The source (S) of the output FET can be connected to 1.1 V to 3.6 V, which allows the output signal to be level translated to another voltage value. The voltage at V+ must be greater than or equal to the voltage at S. The voltage at S must be greater than or equal to the voltage at D (V+ ≥ VS ≥ VD).