The MAX6339 is a precision quad voltage monitor withmicroprocessor (µP) supervisory reset timing. The devicecan monitor up to four system supply voltages withoutany external components and asserts a single reset if anysupply voltage drops below its preset threshold. Thedevice significantly reduces system size and componentcount while improving reliability compared to separateICs or discrete components.

A variety of factory-trimmed threshold voltages are availableto accommodate different supply voltages and toleranceswith minimal external component requirements.The selection includes internally fixed options for monitoring+5.0V, +3.3V, +3.0V, +2.5V, +1.8V, and -5.0V supplieswith -5% and/or -10% tolerances. The device is alsoavailable with one or two user-adjustable thresholdoptions if non-standard thresholds are desired (use externalresistor-divider network).

The quad monitor provides a single active-low reset outputthat is asserted when any monitored input is below itsassociated threshold. The output is open drain with aweak internal pullup (10µA) to IN2. Reset remains low fora reset timeout period (140ms min) after all voltages areabove the selected thresholds. The output is valid as longas either the IN1 or IN2 input voltage remains > 1V.

The MAX6339 is available in a small 6-pin SOT23 packageand operates over the extended (-40°C to +85°C)temperature range.