View r3118-series datasheet:

R3118x SERIES LOW VOLTAGE DETECTOR with individual SENSE pin and delay function NO.EA-242-111104 OUTLINE The R3118x series are CMOS-based voltage detector ICs with individual sense pin, high detector threshold accuracy and delay time, and ultra-low supply current, which can be operated at an extremely low voltage and is used for system reset as an example. Each of these ICs consists of a voltage reference unit, a hysteresis comparator, resistors net for detector threshold setting, an output driver transistor, and a delay circuit. VDD supply pin for the IC and voltage supervisory sense pin are individual, therefore the output pin can keep "L" level even if the sense pin voltage is going down to 0V, or there is no indefinite range for the sense pin. Since a delay circ