DS1231-20 is a simple reset/power-on reset supervisor IC from Analog Devices / Maxim Integrated. It monitors one voltage, offers open drain/open collector output, and is available in an 8-PDIP package.
The Analog Devices DS1231-50+ is a supervisor IC designed for power monitoring. It features a simple reset function and operates within a temperature range of 0°C to 70°C.