LP3809 Micro-Power Voltage Detectors, Reset Of MCU With Delay Time General Description Features The LP3809 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 1.2V to 5V, which covers most digital applications. It features low supply current of 3µA. The LP3809 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 upcrossing the threshold level, the reset signal will be released after a certain delay time. Available in the 5-lead of SOT-23 packages. Pin Configurations Built-in Recovery Delay Include 210ms Internally Fixed Threshold 1.2V to 5V in 0.1V Step No External Components Required High Accuracy 1.5% Low Supply Current 3 A Low Functional Supply Voltage 0.9V N-Channel Open-Drain output Quick Start-Up Applications Computers CPU/MCU/DSP Portable Battery-Powered Equipment Ordering Information LP3809□ - □ □ □ □ □ Pin No. Type A Type B SOT-23 1 RESET GND 2 GND RESET Type A: Type A B: Type B 3 VDD VDD F:PB-Free Package B3: SOT-23 Output Voltage: 12: 1.2V 13: 1.3V 50: 5.5V Typical Application Circuit LP3809-datasheet Oct.-2004 Note: 1. Output Voltage range from 1.2V to 5.0V in 0.1V increments. 2. 2.7V output order is LP3809A-27B3F. 1-1 LP3809 Functional Pin Description Pin Name Pin Function GND Ground RESET Active Low Open-Drain Reset Output VDD Power Pin Function Block Diagram Absolute Maximum Ratings Supply Input Voltage---------------------------------------------------------------------------------------------------6V Power Dissipation, PD @ TA = 25°C SOT-23 --------------------------------------------------------------------------------------------------------------------400mW Package Thermal Resistance SOT-23, θJA -------------------------------------------------------------------------------------------------------------250°C/W ESD Susceptibility HBM (Human Body Mode) ---------------------------------------------------------------------------------------------2kV MM(Machine-Mode)-----------------------------------------------------------------------------------------------------200V Recommended Operating Conditions Supply Input Voltage-----------------------------------------------------------------------------0.3V to 6V Operation Ambient Temperature Range------------------------------------------------−40°C to 85°C Electrical Characteristics Parameter Symbol Test Conditions Min Typ Max Units Quiescent Current IQ VEN ≥ 1.2V, IOUT = 0mA Reset Threshold VTH TA = 27°C Threshold Voltage Accuracy ΔVTH VDD Drop to Reset Delay Trd Drop = VTH -125mV 20 uS Reset Active Time LP3809A/B VDD ≥ 1.02×VTH 210 mS RESET Output Voltage Low VOL 3 = VDD < VTH ISINK >3.5mA 0.4 V Thermal Shutdown Temperature TSD 165 °C LP3809-datasheet Oct.-2004 2-2 3 μA 1.2 1.5 V -1.5 1.5 % LP3809 Typical Operating Characteristics LP3809-datasheet Oct.-2004 3-3 LP3809 LP3809-datasheet Oct.-2004 4-4 LP3809 LP3809-datasheet Oct.-2004 5-5 LP3809 Package Information LP3809-datasheet Oct.-2004 6-6