Preliminary
RT9809
Micro-Power Voltage Detectors
General Description
The RT9809 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 2.5µA.
The RT9809 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.
RT9809 is provided in SOT-23 package.
Features
Internally Fixed Threshold 1.5V to 5V in 0.1V
Step
±
2% Accuracy
Low Supply Current 2.5µA
µ
No External Components Required
Quick Reset within 20µS
µ
Built-in Recovery Delay 400mS
Low Functional Supply Voltage 0.9V
Small 3-Pin SOT-23 Package
Pin Configurations
Part Number
RT9809-
(SOT-23)
1
2
Pin Configurations
TOP VIEW
3
CV
1. GND
2. RESET
3. VDD
Applications
Computers
Controllers
Intelligent Instruments
Critical
µP
and
µC
Power Monitoring
Portable/Battery-Powered Equipment
Typical Application Circuit
VDD
µ
P
RESET
RESET
RT9809
GND
VDD
Ordering Information
RT9809-
Package Type
V : SOT-23
Operating temperature range
C: Commercial standard
Reset Threshold
15 : 1.5V
16 : 1.6V
:
49 : 4.9V
50 : 5.0V
DS9809-00 June 2001
www.richtek-ic.com.tw
1
Preliminary
Absolute Maximum Ratings
Terminal Voltage (with Respect to GND)
VDD
All Other Inputs
Input Current, VDD
Output Current, RESET
Power Dissipation, P
D
@ T
A
= 25°C
SOT-23
Operating Junction Temperature Range
Storage Temperature Range
Package Thermal Resistance
SOT-23,
θ
JA
Lead Temperature (Soldering, 5sec.)
RT9809
-0.3V to 6.0V
-0.3V to VDD+0.3V
20mA
20mA
0.25W
-40°C ~ 125°C
-65°C ~ 125°C
250°C /W
260°C
Electrical Characteristics
(VDD = 3.0, unless specified)
Parameter
Operating VDD (V
OUT
) Range
Supply Current
Reset Threshold
Threshold Voltage Accuracy
V
CC
Drop to Reset Delay
Reset Active Time Out Period
RESET Output Voltage
Note1: 1.5V ~ 5V, step 0.1V
Symbol
V
DD
I
DD
V
TH
∆V
TH
t
RD
t
RP
V
OH
V
OL
V
DD
= 1.5V ~ 5V, I
OUT
= 0
T
A
= 27°C
T
A
= 27°C
V
DD
= 5V, Drop = -20mV
V
DD
= 1.5V, Drop = -20mV
V
DD
≥
1.02×V
TH
V
DD
> V
TH
, I
SOURCE
> 1mA
V
DD
< V
TH
, I
SINK
> 3.5mA
Test Conditions
Min
0.9
--
--
--
--
--
--
--
--
Typ
--
2.5
Note1
--
25
5
400
0.8V
DD
0.2V
DD
Max
6
--
--
2
--
--
--
--
--
Units
V
µA
V
%
µS
mS
V
DS9809-00 June 2001
www.richtek-ic.com.tw
3
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