RICHTEK RT9808-15CB, RT9808-15CV, RT9808-15CX, RT9808-42CB, RT9808-42CV Datasheet
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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.
Applications
Computers
z
Controllers
z
Intelligent Instruments
z
Critical µP and µC Power Monitoring
z
Portable/Battery-Powered Equipment
z
Ordering Information
RT9808-
Package Type
V : SOT-23
X : SOT-89
B : SOT-25
Features
z
Internally Fixed Threshold 1.5V to 5V in 0.1V Step
z ±
±2% Accuracy
±±
Low Supply Current 3µµµµA
z
Quick Reset within 20µµµµS
z
Built-in Recovery Delay 200mS
z
Low Functional Supply Voltage 0.9V
z
N-Channel Open Drain Output
z
Small 3-Pin SOT-23/SOT89 and 5-Pin SOT-25
z
Packages
Pin Configurations
Part Number Pin Configurations
RT9808-CV
(Plastic SOT-23)
RT9808-CX
(Plastic SOT-89)
RT9808-CB
(Plastic SOT-25)
3
2
1
123
54
3
21
TOP VIEW
1. RESET
2. GND
3. VDD
TOP VIEW
1. RESET
2. VDD
3. GND
TOP VIEW
1. RESET
2. VDD
3. GND
4. NC
5. NC
Typical Application Circuit
Operating temperature range
C: Commercial standard
Reset Threshold
15 : 1.5V
VDD
P
µ
Pull
Up
100K
RT9808
GND
VDD
16 : 1.6V
:
RESET
RESET
49 : 4.9V
50 : 5.0V
DS9808-01 January 2002 www.richtek-ic.com.tw
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RT9808
Pin Description
Pin Name Pin Function
GND Ground Pin
RESET Reset Pulse Output, Negative Pulse
VDD Power Pin
NC No Connected
Function Block Diagram
VDD
Preliminary
VSET
Threshold Voltage Setting
Power On Reset
CMP
POR
TIMER
RESET
N
www.richtek-ic.com.tw DS9808-01 January 2002
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Preliminary
RT9808
Absolute Maximum Ratings
z Terminal Voltage (with Respect to GND)
VDD -0.3V to 6.0V
All Other Inputs -0.3V to VDD+0.3V
z Input Current, VDD 20mA
z Output Current, RESET 20mA
z Power Dissipation, P
SOT-23 0.25W
SOT-89 0.5W
SOT-25 0.25W
z Operating Junction Temperature Range -40°C ~ 125°C
z Storage Temperature Range -65°C ~ 125°C
z Package Thermal Resistance
SOT-23, θ
SOT-89, θ
SOT-89, θ
SOT-25, θ
z Lead Temperature (Soldering, 5sec.) 260°C
JA
JC
JA
JA
@ TA = 25°C
D
250°C /W
100°C /W
300°C /W
250°C /W
Electrical Characteristics
(VDD = 3.0, unless specified)
Parameter Symbol Test Conditions Min Typ Max Units
Operating VDD (V
Supply Current
Reset Threshold
Threshold Voltage Accuracy
VCC Drop to Reset Delay t
Reset Active Time Out Period
RESET Output Voltage
Note1: 1.5V ~ 5V, step 0.1V
) Range V
OUT
I
DD
V
∆V
RD
t
RP
V
DD
TH
OL
0.9 -- 6 V
VDD = 1.5V ~ 5V, I
TA = 27°C
TA = 27°C
TH
OUT
= 0
-- 3 --
-- Note1 -- V
-- -- 2 %
Drop = -125mV -- -- 20
VDD ≥ 1.02×V
V
< VTH, I
DD
TH
SINK
> 3.5mA
-- 200 -- mS
-- 0.4 -- V
µA
µS
DS9808-01 January 2002 www.richtek-ic.com.tw
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RT9808
Measuring Circuit
Preliminary
(1) Detection Voltage
V
DD
V
RT9808
(2) Current Consumption
A
V
DD
V
V
DD
V
SS
V
RT9808
DD
R (100kΩ)
OUT
OUT
Oscilloscope
(3) Output Transistor Current
V
DD
RT9808
OUT
P.G
V
SS
(4) Dynamic Response
V
DD
V
DD
V
RT9808
100k
CRT
CL
OUT
Ω
6V
A
SS
V
V
DS
V
SS
V
www.richtek-ic.com.tw DS9808-01 January 2002
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