Document
Preliminary
RT9802
User Programmable Micro-Power Voltage Detectors
General Description
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Features
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The RT9802 is a micro-power voltage detector supervising the power supply voltage level for microprocessors (μP) or digital systems. It provides user programmable threshold levels with 0.1V step ranging from 1.5V to 5V, which covers most digital applications. It features low supply current of 3μA. Selection of VTH is easily achieved through 3 pins connected to GND, VDD or floating for different threshold voltage settings. Two versions of threshold voltages, 1.5V to 4V and 2.5V to 5V, which are programmed in factory are offered by customer demands. The RT9802 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. Reset signal will release after VDD is recovered and lasts for the whole period of Reset Active Time-out period. RT9802 is CMOS, active-low output and provided in SOT-23-6 package.
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User Programmable Threshold 1.5V to 5V in 0.1V Step with ± 3% Accuracy Low Supply Current 3μA Quick Reset within 20μs Built-in Recovery Delay 200ms Low Functional Supply Voltage 0.9V Small SOT-23-6 Package RoHS Compliant and 100% Lead (Pb)-Free
Applications
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Computers Controllers Intelligent Instruments Critical μP and μC Power Monitoring Portable/Battery-Powered Equipment
Marking Information
For marking information, contact our sales representative directly or through a RichTek distributor located in your area, otherwise visit our website for detail.
Ordering Information
RT9802Package Type E : SOT-23-6 Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard) Reset Threshold A : 2.5V to 5V B : 1.5V to 4V
Pin Configurations
(TOP VIEW)
VSET1 VSET2 VDD 6 1 5 2 4 3
VSET0 GND RESET
SOT-23-6 Note : RichTek Pb-free and Green products are : `RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. `Suitable for use in SnPb or Pb-free soldering processes. `100%matte tin (Sn) plating. Note : There is no pin1 indicator on top mark for SOT-23-6 type, and pin 1 will be lower left pin when reading top mark from left to right.
DS9802-07 March 2007
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RT9802
Typical Application Circuit
Preliminary
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VDD
μP GND RESET
VSET0
VSET1
RT9802 GND VSET2 RESET VDD
RT9802B VTH = 2.5V in this example
Functional Pin Description
Pin Name VSET0 GND RESET VDD VSET1 VSET2 Pin Function Threshold Voltage Selection Pin 1 Ground Pin Reset Pulse Output, Negative Pulse Power Pin Threshold Voltage Selection Pin 2 Threshold Voltage Selection Pin 3
Function Block Diagram
VDD
Internal Clock
VSET0 VSET1 VSET2
P MOS VSET CMP Timer N MOS Threshold Voltage Setting GND POR Power On Reset RESET
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DS9802-07 March 2007
Preliminary Absolute Maximum Ratings
RT9802
Terminal Voltag.