General Description
The RT9809 is a micro-power voltage detector supervising the power supply voltage level for microprocessors (µP) or digital systems. It provides internally fixed threshold levels with 0.1V per step ranging from 1.5V to 5V, which covers most digital applications. It features low supply current of 2.5µA.
The RT9809 performs supervisory function by sending out a reset signal whenever the VDD voltage falls below a preset threshold level. This reset signal will last the whole period before VDD recovering. Once VDD recovered up-crossing the threshold level, the reset signal will be released after a certain delay time. A 5% hysteresis splits the rising and falling threshold levels.

FEATUREs
• Internally Fixed Threshold 1.5V to 5V in 0.1V Step
• ±2% Accuracy
• Low Supply Current 2.5µA
• No External Components Required
• Quick Reset within 20µS
• Built-in Recovery Delay 400mS
• Low Functional Supply Voltage 0.9V
• Small 3-Pin SOT-23 Package

APPLICATIONs
• Computers
• Controllers
• Intelligent Instruments
• Critical µP and µC Power Monitoring
• Portable/Battery-Powered Equipment