
Preliminary
RT9811
DS9811-00 June 2001
www.richtek-ic.com.tw
1
Micro-Power Voltage Detectors
General Description
The RT9811 is a micro-power voltage detector with
de-glitched manual reset input supervising the power
supply voltage level for microprocessors (
μ
P) 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 2.5
μ
A.
The RT9811 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 after a certain delay
time. A 5% hysteresis splits the rising and falling
threshold levels. To pull reset signal low manually,
just pull the manual reset input (MR) below the
specified V
IL
level.
RT9811 is provided in SOT-25 package.
Applications
z
Computers
z
Controllers
z
Intelligent Instruments
z
Critical
μ
P and
μ
C Power Monitoring
z
Portable/Battery-Powered Equipment
Ordering Information
RT9811-
Features
z
Internally Fixed Threshold 1.5V to 5V in 0.1V
Step
z
±
2% Accuracy
z
Low Supply Current 2.5
μ
A
z
No External Components Required
z
Quick Reset within 20
μ
S
z
Built-in Recovery Delay 400mS
z
100nS Glitch Immunity of Manual Reset Input
z
Low Functional Supply Voltage 0.9V
z
Small 4-Pin SOT-25 Package
Pin Configurations
Part Number
Pin Configurations
RT9811-
CB
(SOT-25)
TOP VIEW
1. GND
2. NC
3. RESET
4. MR
5. VDD
Typical Application Circuit
5
4
3
2
1
Operating temperature range
C: Commercial standard
Reset Threshold
15 : 1.5V
16 : 1.6V
:
49 : 4.9V
50 : 5.0V
Package Type
B : SOT-25
VDD
μ
P
RESET
RT9811
VDD
RESET
MR
GND