General Description
The RT9811 is a micro-power voltage detector with de-glitched manual reset input 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 RT9811 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. To pull reset signal low manually, just pull the manual reset input (MR) below the specified VIL level.

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
• 100nS Glitch Immunity of Manual Reset Input
• Low Functional Supply Voltage 0.9V
• Small 4-Pin SOT-25 Package

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