RT9818
Micro-Power Voltage Detectors
General Description
The RT9818 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 1.2V to 5V, which covers most digital applications. It
features low supply current of 3μA. The RT9818 performs
supervisory function by sending out a reset signal
whenever the V
DD
voltage falls below a preset threshold
level. This reset signal will last the whole period before
V
DD
recovering. Once V
DD
recovered upcrossing the
threshold level, the reset signal will be released after a
certain delay time. RT9818 is provided in SC-82, SC-70-3,
SOT-23-3, SOT-23-5 and SOT-89 packages.
Features
Internally Fixed Threshold 1.2V to 5V in 0.1V Step
High Accuracy
±
1.5%
Low Supply Current 3μA
μ
No External Components Required
μ
Quick Reset within 20μs
Built-in Recovery Delay Include 0ms, 55ms, 220ms,
450ms Options
Low Functional Supply Voltage 0.9V
N-Channel Open-Drain Output
Small SC-82, SC-70-3, SOT-23-3, SOT-23-5, SOT-89
Packages
RoHS Compliant and 100% Lead (Pb)-Free
Applications
Computers
Controllers
Intelligent Instruments
Critical
μP
and
μC
Power Monitoring
Portable/Battery-Powered Equipment
Ordering Information
RT9818
-
Package Type
U3 : SC-70-3
V : SOT-23-3
VL : SOT-23-3 (L-Type)
B : SOT-23-5
X : SOT-89
Y : SC-82
YR : SC-82 (R-Type)
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
Threshold Voltage
12 : 1.2V
13 : 1.3V
:
49 : 4.9V
50 : 5.0V
Reset Active Timeout Period
A = 0ms
(RESET)
B = 55ms
(RESET)
C = 220ms
(RESET)
D = 450ms
(RESET)
E = 0ms
(RESET)
F = 55ms
(RESET)
G = 220ms
(RESET)
H = 450ms
(RESET)
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.
Typical Application Circuit
100k
Pull Up
VDD
μP
RESET/
RESET
RT9818
GND
VDD
RESET/
RESET
Note :
RichTek Pb-free and Green products are :
RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
100%matte tin (Sn) plating.
DS9818-05 March 2007
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
