View r3130n r3131n-series datasheet:

Low Voltage Detector with built-in Delay Circuit R3130N×××A/C, R3131N×××A/C APPLICATION MANUAL NO. EA-073-0012 Low Voltage Detector with built-in Delay Circuit R3130N×××A/C, R3131N×××A/C OUTLINE R3130N/R3131N Series are low voltage detector ICs with built-in delay circuit, high Detector Threshold accuracy and ultra low supply current by CMOS process, which can be operated at low voltage. These ICs can be used as system reset generator, and each of these ICs consists of a voltage reference, a com- parator, resistors for setting voltage detector threshold, an output driver transistor, and an output delay generator. Detector threshold is fixed internally with high accuracy and requires no adjustment. When Supply Voltage crosses a setting detector threshold voltag