The MAX6339 is a precision quad voltage monitor with microprocessor (µP) supervisory reset timing. The device can monitor up to four system supply voltages without any external components and asserts a single reset if any supply voltage drops below its preset threshold. The device significantly reduces system size and component count while improving reliability compared to separate ICs or discrete components.A variety of factory-trimmed threshold voltages are available to accommodate different supply voltages and tolerances with 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 supplies with -5% and/or -10% tolerances. The device is also available with one or two user-adjustable threshold options if non-standard thresholds are desired (use external resistor-divider network).The quad monitor provides a single active-low reset output that is asserted when any monitored input is below its associated threshold. The output is open drain with a weak internal pullup (10µA) to IN2. Reset remains low for a reset timeout period (140ms min) after all voltages are above the selected thresholds. The output is valid as long as either the IN1 or IN2 input voltage remains > 1V.The MAX6339 is available in a small 6-pin SOT23 package and operates over the extended (-40°C to +85°C) temperature range.ApplicationsComputers: Desktop, Workstation, ServerData Storage EquipmentHigh-End PrintersIndustrial EquipmentNetwork EquipmentSet-Top BoxesTelecommunications