Two-rail supervisor in an 8-pin DIP
The ICL7665ACPA+ is a multi-voltage supervisor from Analog Devices that monitors two independent supply rails, asserting a reset when either falls below the programmed threshold. The reset output is active high with an open-drain or open-collector stage, which lets you wire-OR it with other fault signals on the same pull-up rail.
What the ratings mean for the BOM
The reset timeout is under 1 ms minimum, which means the downstream processor sees the reset de-assert within a millisecond after both supplies are stable, avoiding a race condition on the power-up sequence. Thresholds are adjustable via external resistor dividers, so the same part number adapts to a 3.3 V / 1.8 V pair or a 5 V / 3.3 V pair without a factory trim.
The 8-pin PDIP (0.300" body width, 7.62 mm) is a through-hole package that plugs into a standard 0.100" pitch socket or solder-in hole pattern — no fine-pitch soldering required. Commercial temperature grade (0°C to 70°C) suits benchtop instrumentation, telecom line cards, and indoor industrial control panels that stay above freezing.