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
TH
is easily achieved through 3 pins
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
Features
User Programmable Threshold 1.5V to 5V in
0.1V Step with
±
3% Accuracy
Low Supply Current 3µA
µ
Quick Reset within 20µS
µ
Built-in Recovery Delay 200mS
Low Functional Supply Voltage 0.9V
Small SOT-26 Package
Applications
Computers
Controllers
Intelligent Instruments
Critical
µP
and
µC
Power Monitoring
Portable/Battery-Powered Equipment
Pin Configurations
Part Number
RT9801 CE
(Plastic SOT-26)
Pin Configurations
TOP VIEW
6
5
4
provided in SOT-26 package.
1
2
3
Ordering Information
RT9801
Package Type
E : SOT-26
Operating temperature range
C: Commercial standard
Reset Threshold
A : 2.5V~5V
B : 1.5V~4V
1.
2.
3.
4.
5.
6.
VSET0
GND
RESET
VDD
VSET2
VSET1
Typical Application Circuit
VSET0 VSET1
µP
GND
VDD
RESET
RESET
Pull Up
RT9801B V
TH
= 2.5V in this example
VDD
RT9801
GND
VSET2
DS9801-00 January 2002
www.richtek-ic.com.tw
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
