Preliminary
RT9808
Micro-Power Voltage Detectors
General Description
The RT9808 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 1.5V to 5V, which covers most digital
applications. It features low supply current of 3µA.
The RT9808 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 if VDD is above
threshold and last for the whole period of reset active
time out.
RT9808 is n-channel, open-drain output.
Features
Internally Fixed Threshold 1.5V to 5V in 0.1V Step
±
2% Accuracy
Low Supply Current 3µA
µ
Quick Reset within 20µS
µ
Built-in Recovery Delay 200mS
Low Functional Supply Voltage 0.9V
N-Channel Open Drain Output
Small 3-Pin SOT-23/SOT89 and 5-Pin SOT-25
Packages
Pin Configurations
Part Number
RT9808-
CV
1
Pin Configurations
3
TOP VIEW
1. RESET
2. GND
3. VDD
TOP VIEW
1. RESET
2. VDD
3. GND
TOP VIEW
(Plastic SOT-23)
2
Applications
Computers
Controllers
Intelligent Instruments
Critical
µP
and
µC
Power Monitoring
Portable/Battery-Powered Equipment
RT9808-
CX
(Plastic SOT-89)
1
2
3
RT9808-
CB
5
4
(Plastic SOT-25)
Ordering Information
RT9808-
Package Type
V : SOT-23
X : SOT-89
B : SOT-25
Operating temperature range
C: Commercial standard
Reset Threshold
15 : 1.5V
16 : 1.6V
:
49 : 4.9V
50 : 5.0V
µP
RESET
1
2
3
1.
2.
3.
4.
5.
RESET
VDD
GND
NC
NC
Typical Application Circuit
VDD
Pull
100K
Up
RT9808
GND
VDD
RESET
DS9808-01 January 2002
www.richtek-ic.com.tw
1
ETC [ ETC ]
