Micro-Power Voltage Detectors
RT9819
General Description
The RT9819 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 ra nging
from 1.2V to 5V , which covers most digital applications. It
features low supply current of 3μA. The RT9819 performs
supervisory function by sending out a reset signal
whenever the V
voltage falls below a preset threshold
DD
level. This reset signal will last the whole period before
VDD recovering. Once VDD recovered upcrossing the
threshold level, the reset signal will be released after a
certain delay time. RT9819 is provided in SC-70-3,
SC-82 and SOT -23-3 packages.
Ordering Information
RT9819
Note :
Richtek 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.
Package Type
U3 : SC-70-3
V : SOT-23-3
VL : SOT-23-3 (L-Type)
Y : SC-82
YR : SC-82 (R-Type)
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
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)
Features
zz
Internally Fixed Threshold 1.2V to 5V in 0.1V Step
z
zz
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z High Accuracy
zz
zz
z Low Supply Current 3
zz
zz
z No External Components Required
zz
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z Quick Reset within 20
zz
zz
z Built-in Recovery Delay Include 0ms, 55ms, 220ms,
zz
±±
±1.5%
±±
μμ
μA
μμ
μμ
μs
μμ
450ms Options
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z Low Functional Supply Voltage 0.9V
zz
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z CMOS Push-Pull Output
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z Small SC-70-3, SC-82 and SOT-23-3 Packages
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z RoHS Compliant and 100% Lead (Pb)-Free
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Applications
z Computers
z Controllers
z Intelligent Instruments
z Critical μP and μC Power Monitoring
z Portable/Battery-Powered Equipment
Typical Application Circuit
VDD
up
RESET/
RESET
RT9819
VDDGND
RESET/
RESET
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
DS9819-07 April 2011 www.richtek.com
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RT9819
Pin Configurations
(TOP VIEW)
GND
VDD
3
2
RESET/
RESET
GND
4
RESET/
RESET
NC
3
2
VDD
Functional Pin Description
Pin Name Pin Function
GND Ground
RESET Active Low Push-Pull Reset Output
RESET Active High Push-Pull Reset Output
VDD Power Pin
Function Block Diagram
VDD
RESET/
RESET
4
VDD
NC
3
2
GND
VDD
GND
VDD
3
2
RESET/
RESET
RESET/
RESET
SOT-23-3 (L-Type)SOT-23-3SC-70-3 SC-82 (R-Type)SC-82
VDD
3
2
GND
VSET
Threshold
Voltage Setting
CMP
POR
Power On Reset
Timer
P MOS
N MOS
RESET/
RESET
DS9819-07 April 2011www.richtek.com
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RT9819
Absolute Maximum Ratings (Note 1)
z T erminal V oltage (with Respe ct to GND)
VDD------------------------------------------------------------------------------------------------------------------------ −0.3V to 6.0V
z All Other Inputs -------------------------------------------------------------------------------------------------------- −0.3V to V
z Input Current, I
z Power Dissipation, PD @ T
----------------------------------------------------------------------------------------------------- 20mA
VDD
= 25°C
A
SC-70-3/SC-82 --------------------------------------------------------------------------------------------------------- 0.25W
SOT-23-3 ---------------------------------------------------------------------------------------------------------------- 0.4W
z Package Thermal Resistance (Note 2)
SC-70-3/SC-82, θJA--------------------------------------------------------------------------------------------------- 400°C /W
SOT-23-3, θJA----------------------------------------------------------------------------------------------------------- 250°C /W
z Lead Te mperature (Soldering, 10sec.)---------------------------------------------------------------------------- 260°C
z Storage T emperature Range ---------------------------------------------------------------------------------------- −65°C to 125°C
z ESD Susceptibility (Note 3)
HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 2kV
MM (Ma chine Mode)-------------------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions (Note 4)
DD
+0.3V
z Junction T emperature Range---------------------------------------------------------------------------------------- −40°C to 125°C
z Ambient T emperature Range---------------------------------------------------------------------------------------- −40°C to 85°C
Electrical Characteristics
(VDD = 3V, TA = 25°C, unless otherwise specified)
Parameter Symbol Test Conditions Min Typ Max Units
Operati ng VDD (V
) Range VDD
OUT
Supply Current IDD V
Reset Threshold VTH -- 1.2 to 5.0 -- V
Threshold Voltage Accuracy ΔVTH −1.5 -- +1.5 %
Threshold Voltage Hysteresis V
HYS
VDD Drop to Reset Delay tRD Drop = VTH −125mV -- 20 -- μs
RT9819A/E
Reset Active
Time Out Period
RT9819B/F 35 55 75 ms
VDD ≥ 1.02 × VTH
t
RT9819C/G 143 220 297 ms
RP
RT9819D/H 292 450 608 ms
RESET Outp ut Voltage Low
V
OL
RT9819A/B/C/D 0.9 -- 6
V
RT9819E/F/G/H 1.1 -- 6
= 3V , VDD = 4.5V -- 3 8 μA
TH
-- 0.01 VTH -- V
-- 0 -- ms
V
< V
DD
≥ 3V
V
TH
VDD < V
≥ 1.8V
V
TH
V
TH(MIN)
= 0.5mA
I
SINK
TH(MIN)
TH(MIN)
,I
SINK
,I
SINK
> VDD > 1V,
= 3.5mA,
= 1.2mA,
-- -- 0.4
-- -- 0.3
-- -- 0.3
V
To be continued
DS9819-07 April 2011 www.richtek.com
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RT9819
Parameter Symbol Test Conditions Min Typ Max Units
V
> V
DD
TH(MAX)
RESET Output Voltage High
V
OH
RESET Output Voltage Low VOL
RESET Output Voltage High VOH
I
SOURCE
VDD > V
I
SOURCE
VDD > V
I
SOURCE
V
V
VDD > V
V
VDD > V
V
1.1V < V
I
SOURCE
1.8V < VDD < V
I
SOURCE
DD
TH
TH
TH
= 800μA, V
TH(MAX)
= 500μA, V
TH(MAX)
= 200μA, V
> V
TH(MAX)
≥ 3V
TH(MAX)
≥ 1.8V
TH(MAX)
≥ 1.2V
DD
= 200μA
= 500μA
3V < VDD < V
I
SOURCE
Note 1. Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device. These are for
stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods may remain possibility to affect device reliability.
Note 2. θ
Note 3. Devices are ESD sensitive. Handling precaution is recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
is measured in the natural convection at TA = 25°C on a low effective thermal conductivity test board of
JA
JEDEC 51-3 thermal measurement standard.
= 800μA
< V
TH(MIN)
,
TH
,
TH
,
TH
,I
SINK
,I
SINK
,I
SINK
TH(MIN)
TH(MIN)
,
≥ 3V
≥ 1.8 V
≥ 1.1 V
= 3. 5mA ,
= 1. 2mA ,
= 0. 5mA ,
,
,
−1.5 -- --
V
DD
0.8 V
0.8 V
-- --
DD
-- --
DD
-- -- 0.4
-- -- 0.3
-- -- 0.3
0.8 V
0.8 V
V
DD
-- --
DD
-- --
DD
−1.5 -- --
V
V
V
DS9819-07 April 2011www.richtek.com
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