The MAX6803/MAX6804/MAX6805 microprocessor (µP) supervisory circuits monitor the power supplies in 2.85V to 5.0V µP and digital systems. They increase circuit reliability and reduce cost by eliminating external components and adjustments. They also feature a debounced manual reset input.

These devices perform a single function: they assert a reset signal whenever the VCC supply voltage declines below a preset threshold or whenever manual reset is asserted. Reset remains asserted for a preset timeout period after VCC has risen above the reset threshold or after manual reset is deasserted. The only difference among the three devices is their output. The MAX6804 (push/pull) and MAX6805 (open-drain) have an active-low RESET output, while the MAX6803 (push/pull) has an active-high RESET output. The MAX6803/MAX6804 are guaranteed to be in the correct state for VCC down to 0.7V. The MAX6805 is guaranteed to be in the correct state for VCC down to 1.0V.

The reset comparator in these ICs is designed to ignore fast transients on VCC. Reset thresholds are factory-trimmable between 2.63V and 4.80V, in approximately 100mV increments. These devices are available with a 1ms min, 20ms min, or 100ms min reset timeout period. Ideal for space-critical applications, the MAX6803/MAX6804/MAX6805 come packaged in a 4-pin SOT143. For a lower threshold voltage version, see the MAX6335/MAX6336/MAX6337.