The MAX823/MAX824/MAX825 microprocessor (μP) supervisory circuits combine reset output, watchdog, and manual reset input functions. They significantly improve system reliability and accuracy compared to separate ICs or discrete components. The MAX823/MAX824/MAX825 are specifically designed to ignore fast transients on VCC. Seven preprogrammed reset threshold voltages are available. All three devices have an active-low reset output, which is guaranteed to be in the correct state for VCC down to 1V. The MAX823 also offers a watchdog input and manual reset input. The MAX824 offers a watchdog input and a complementary active-high reset. The MAX825 offers a manual reset input and a complementary active-high reset.
The MAX823, MAX824, and MAX825 are 5‑pin microprocessor supervisory circuits that combine reset output, watchdog timer, and manual reset functions in SOT‑23 and SC70 packages. They improve system reliability by providing active‑low or active‑high reset outputs that remain valid down to 1 V VCC and include seven selectable reset‑threshold voltages.
The datasheet provides electrical characteristics, ordering information, pin descriptions, typical operating curves, and package dimensions. It also outlines application notes such as watchdog timing, manual reset implementation, and bidirectional reset interfacing.
| Operating Current (MAX823L/M, SC70) | 6 µA |
|---|---|
| Operating Current (MAX825T/S/R/Z/Y, SC70) | 2 µA |
| Watchdog Timer Timeout | 1.6 s |
| Power‑On Reset Minimum Time | 140 ms |
| Reset Threshold Options | Seven preprogrammed voltages |
| Operating Temperature Range | -40 °C to +125 °C |
| Reset Output Pull‑up Current (L/M versions) | 800 µA |
The watchdog timer has a timeout of 1.6 seconds.
There are seven preprogrammed reset threshold voltages.
The operating current is 6 µA for the MAX823L/M SC70 version.