RICHTEK RT9801ACE, RT9801BCE Datasheet
Preliminary
RT9801
User Programmable Micro-Power Voltage Detectors
General Description
The RT9801 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 V
is easily achieved through 3 pins
TH
connected to GND, VDD or floating for different
threshold voltage settings. Two versions of threshold
voltages, 1.5V ~ 4V and 2.5V ~ 5V, which are
programmed in factory are offered by customer
demands.
The RT9801 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.
RT9801 is N-channel, open-drain output and
provided in SOT-26 package.
Ordering Information
Features
z
User Programmable Threshold 1.5V to 5V in
0.1V Step with ±±±±3% Accuracy
z
Low Supply Current 3µµµµA
z
Quick Reset within 20µµµµS
z
Built-in Recovery Delay 200mS
z
Low Functional Supply Voltage 0.9V
z
Small SOT-26 Package
Applications
z Computers
z Controllers
z Intelligent Instruments
z Critical µP and µC Power Monitoring
z Portable/Battery-Powered Equipment
Pin Configurations
Part Number Pin Configurations
321
TOP VIEW
1. VSET0
2. GND
3. RESET
4. VDD
5. VSET2
6. VSET1
RT9801CE
(Plastic SOT-26)
64
5
RT9801
Typical Application Circuit
Package Type
E : SOT-26
Operating temperature range
C: Commercial standard
P
Reset Threshold
A : 2.5V~5V
B : 1.5V~4V
DS9801-00 January 2002 www.richtek-ic.com.tw
µ
GND
VDD
RESET
RT9801B V
VSET0
GND
RESET
Pull Up
= 2.5V in this example
TH
VSET1
RT9801
VSET2
VDD
1
RT9801
Pin Description
Pin Name Pin Function
VSET0 Threshold Voltage Selection Pin 1
GND Ground Pin
RESET Reset Pulse Output, Negative Pulse
VDD Power Pin
VSET1 Threshold Voltage Selection Pin 2
VSET2 Threshold Voltage Selection Pin 3
Function Block Diagram
Internal Clock
VDD
Preliminary
VSET0
VSET1
VSET2
Threshold Voltage Setting
VSET
CMP
POR
Power On Reset
TIMER
N
RESET
www.richtek-ic.com.tw DS9801-00 January 2002
2
Loading...