A typical application for TLV803E, TLV809E, and TLV810E devices is voltage rail monitoring. This rail can be the input power supply or the output of an LDO or DC/DC converter. Figure 9-1 shows the TLV803EA29 monitoring the supply rail for a DSP, FPGA, or ASIC. This rail is at 3.3 V and generated by an LDO with an input power supply of 5 V. The supervisor is needed to make sure that the supply to the MCU/ASIC/FPGA/DSP is above a certain voltage threshold. If the supply voltage drops below a certain threshold, supervisor generates a reset output to indicate to the MCU that the supply is going down so that the MCU can take actions to save register data before supply enters brown-out conditions.