RT9834

®
RT9834
Micro-Power Voltage Detector with Manual Reset
General Description
Features
The RT9834 is a micro-power voltage detector with
deglitched manual reset input 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
RT9834 performs supervisory function by sending out a
reset signal whenever the VDD voltage falls below a preset
z
threshold 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. To pull reset signal low manually,
just pull the manual reset input (MR) below the specified
VIL level. The RT9834 is available in the SC-82 and
SOT-143 packages.
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For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
No External Components Required
μs
Quick Reset within 20μ
Built-in Recovery Delay : 0ms, 55ms, 220ms, 450ms
Options
800ns Glitch Immunity of Manual Reset Input
Low Functional Supply Voltage 0.9V
CMOS Push-Pull Output
Small SC-82 and SOT-143 Packages
RoHS Compliant and Halogen Free
Applications
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Marking Information
Internally Fixed Threshold 1.2V to 5V in 0.1V Step
High Accuracy ±1.5%
Low Supply Current 3μ
μA
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Computers
Controllers
Intelligent Instruments
Critical μP and μC Power Monitoring
Portable/Battery-Powered Equipment
Simplified Application Circuit
VDD
RT9834
VDD
MR
µp
RESET/
RESET
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DS9834-00 May 2013
RESET/ GND
RESET
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RT9834
Ordering Information
RT9834
Pin Configurations
(TOP VIEW)
Package Type
H : SOT-143
Y : SC-82
VDD
MR
4
3
2
Lead Plating System
G : Green (Halogen Free and Pb Free)
GND
Threshold Voltage
12 : 1.2V
13 : 1.3V
:
49 : 4.9V
50 : 5.0V
RESET/
RESET
SOT-143
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)
VDD
MR
4
3
2
GND RESET/
RESET
SC-82
Note :
Richtek products are :
`
RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
`
Suitable for use in SnPb or Pb-free soldering processes.
Functional Pin Description
Pin No.
1
Pin Name
Pin Function
GND
Ground.
RESET
Active Low Push-Pull Reset Output.
RESET
Active High Push-Pull Reset Output.
3
MR
Manual Reset.
4
VDD
Power.
2
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is a registered trademark of Richtek Technology Corporation.
DS9834-00 May 2013
RT9834
Function Block Diagram
VDD
VDD
MR
P MOS
VSET
CMP
RESET/
RESET
Timer
N MOS
Threshold
Voltage Setting
POR
Power On Reset
Operation
When VDD is lower than threshold voltage set by VSET
circuit, the RESET output becomes high. If VDD remains
higher than the threshold voltage with a hysteresis voltage,
Timer will be active. After a specific delay time, the RESET
output becomes low. There is an internal pull-high resistor
connected to the MR pin. MR resets the RT9834 only
when it is pulled low. When MR releases and waits for a
delay time, output returns to its normal state related to
VDD. The RESET pin is a Pull-Push output, and it will
pull the output high to VDD, low to Ground. Adding a pullhigh resistor tied to any power which higher than VDD is
forbidden.
Timer
The Timer provides four kinds of delay time options
including 0ms, 55ms, 220ms, and 450ms.
VSET
The VSET generates a fixed threshold voltage.
CMP
Voltage Comparator which compares the voltage difference
between threshold voltage and VDD.
POR
Power on reset. It will set all digital logic to the right state
when power on.
Copyright © 2013 Richtek Technology Corporation. All rights reserved.
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is a registered trademark of Richtek Technology Corporation.
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3
RT9834
Absolute Maximum Ratings
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(Note 1)
Terminal Voltage (with Respect to GND)
VDD --------------------------------------------------------------------------------------------------------------------- −0.3V to 6V
All Other Inputs ----------------------------------------------------------------------------------------------------- −0.3V to (VDD + 0 .3V)
Input Current, IVDD -------------------------------------------------------------------------------------------------- 20mA
Power Dissipation, PD @ TA = 25°C
SOT-143 -------------------------------------------------------------------------------------------------------------- 0.44W
SC-82 ----------------------------------------------------------------------------------------------------------------- 0.29W
Package Thermal Resistance (Note 2)
SOT-143, θJA --------------------------------------------------------------------------------------------------------- 228.1°C/W
SC-82, θJA ------------------------------------------------------------------------------------------------------------ 345.6°C/W
Lead Temperature (Soldering, 10sec.) ------------------------------------------------------------------------- 260°C
Storage Temperature Range ------------------------------------------------------------------------------------- −65°C to 125°C
ESD Susceptibility (Note 3)
HBM (Human Body Model) --------------------------------------------------------------------------------------- 2kV
Recommended Operating Conditions
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(Note 4)
Junction Temperature Range ------------------------------------------------------------------------------------- −40°C to 125°C
Ambient Temperature Range ------------------------------------------------------------------------------------- −40°C to 85°C
Electrical Characteristics
(VDD = 3V, TA = 25°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
RT9834A/B/C/D
0.9
--
6
RT9834E/F/G/H
1.1
--
6
--
3
8
μA
--
1.2 to 5
--
V
Operating VDD (VOUT) Range
VDD
Supply Current
IDD
Reset Threshold
VTH
Threshold Voltage Accuracy
ΔVTH
−1.5
--
1.5
%
Threshold Voltage Hysteresis
VHYS
--
0.01 VTH
--
V
VDD Drop to Reset Delay
tRD
--
20
--
μs
--
0
--
35
55
75
143
220
297
292
450
608
--
--
0.4
--
--
0.3
--
--
0.3
VTH = 3V, VDD = 4.5V
Drop = VTH −125mV
RT9834A/E
Reset Active
Timeout Period
RT9834B/F
RT9834C/G
tRP
VDD ≥ 1.02 x VTH
RT9834D/H
VDD < VTH(MIN) ,ISINK = 3.5mA,
VTH ≥ 3V
RESET Output Voltage Low
VOL
VDD < VTH(MIN) ,ISINK = 1.2mA,
VTH ≥ 1.8V
VTH(MIN) > VDD > 1V,
ISINK = 0.5mA
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V
ms
V
is a registered trademark of Richtek Technology Corporation.
DS9834-00 May 2013
RT9834
Parameter
Symbol
Test Conditions
Min
Typ
Max
VDD − 1.5
--
--
0.8 VDD
--
--
0.8 VDD
--
--
--
--
0.4
--
--
0.3
--
--
0.3
0.8 VDD
--
--
0.8 VDD
--
--
VDD − 1.5
--
--
--
0
--
35
55
75
RT9834C/G
143
220
297
RT9834D/H
292
450
608
V DD > VTH(MAX),
ISOURCE = 800μA, VTH ≥ 3V
RESET Output Voltage High
RESET Output Voltage Low
RESET Output Voltage High
V OH
V OL
V OH
V DD > VTH(MAX),
ISOURCE = 500μA, VTH ≥ 1.8V
V DD > VTH(MAX),
ISOURCE = 200μA, VTH ≥ 1.1V
V DD > VTH(MAX), ISINK = 3.5mA,
V TH ≥ 3V
V DD > VTH(MAX), ISINK = 1.2mA,
V TH ≥ 1.8V
V DD > VTH(MAX), ISINK = 0.5mA,
V TH ≥ 1.2V
1.1V < V DD < VTH(MIN),
ISOURCE = 200μA
1.8V < V DD < VTH(MIN),
ISOURCE = 500μA
3V < VDD < VTH(MIN),
ISOURCE = 800μA
RT9834A/E
MR Active
Timeout Period
RT9834B/F
MR Input Voltage Logic-High
Threshold
Logic-Low
tMR
V MR_H
V DD > VTH(MAX)
0.75 x V DD
--
V DD
V MR_L
V DD > VTH(MAX)
--
--
0.25 x V DD
Unit
V
V
V
ms
V
Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and 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 may
affect device reliability.
Note 2. θJA is measured at TA = 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7.
Note 3. Devices are ESD sensitive. Handling precaution is recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Copyright © 2013 Richtek Technology Corporation. All rights reserved.
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RT9834
Typical Application Circuit
VDD
RT9834
4 VDD
MR
3
µp
RESET/
RESET
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2 RESET/
1
GND
RESET
is a registered trademark of Richtek Technology Corporation.
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RT9834
Typical Operating Characteristics
Nch Driver Output Current vs. VDS
Nch Driver Output Current vs. VDS
2.4
60
RT9834A-12
VDD = 1.1V
VDD = 2.8V
50
Output Current (mA)
Output Current (mA)
2.0
RT9834C-30
1.6
1.2
VDD = 1V
0.8
0.4
VDD = 2.5V
40
30
VDD = 2V
20
VDD = 1.5V
10
0.0
0
0
0.3
0.6
0.9
1.2
1.5
0
0.5
1
1.5
VDS (V)
RT9834A-45
3.5
RT9834A
6
Output Voltage (V)
Output Current (mA)
3
Output Voltage vs. Input Voltage
7
100
80
VDD = 4.4V
= 4V
= 3.5V
= 3V
= 2.5V
= 2V
= 1.5V
60
40
20
5
4
5V
3
2
3V
2.9V
1
0
0
0
1
2
3
4
5
0
1
VDS (V)
2
3
4
5
6
Input Voltage (V)
Supply Current vs. Input Voltage
Supply Current vs. Input Voltage
4
6
RT9834A-12
RT9834C-30
5
Supply Current IDD (µA)
Supply Current (µA)
2.5
VDS (V)
Nch Driver Output Current vs. VDS
120
2
80°C
4
25°C
3
2
−30°C
1
80°C
3
25°C
2
−30°C
1
0
0
0
1
2
3
4
5
Input Voltage (V)
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0
1
2
3
4
5
6
Input Voltage (V)
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RT9834
Supply Current vs. Input Voltage
4
Power-Down Reset Delay vs. Temperature
15
Power-Down Reset Delay (µs)
RT9834A-45
Supply Current (µA)
80°C
3
25°C
−30°C
2
1
RT9834A-12
12
9
VDROP = 200mV
VDROP = 150mV
6
VDROP = 250mV
3
0
0
0
1
2
3
4
5
-50
6
-25
0
Power-Down Reset Delay vs. Temperature
RT9834C-30
40
35
30
25
VDROP = 200mV
20
VDROP = 150mV
15
VDROP = 250mV
10
5
0
75
100
125
RT9834A-45
40
35
30
VDROP = 200mV
25
VDROP = 150mV
20
15
VDROP = 250mV
10
5
0
-50
-25
0
25
50
75
100
125
-50
-25
0
Temperature (°C)
50
75
100
125
Nch Driver Sink Current vs. Input Voltage
Nch Driver Sink Current vs. Input Voltage
50
RT9834C-30, VDS = 0.5V
RT9834A-45, VDS = 0.5V
−30°C
Sink Current I SINK (mA)
−30°C
30
25°C
20
25
Temperature (°C)
40
Sink Current I SINK (mA)
50
Power-Down Reset Delay vs. Temperature
45
Power-Down Reset Delay (µs)
Power-Down Reset Delay (µs)
45
25
Temperature (°C)
Input Voltage (V)
80°C
10
40
25°C
30
80°C
20
10
0
0
0
0.5
1
1.5
2
2.5
3
Input Voltage (V)
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3.5
0
1
2
3
4
5
Input Voltage (V)
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DS9834-00 May 2013
RT9834
Reset Threshold Deviation vs. Temperature
Pch Driver Output Current vs. Input Voltage
25
RT9834
RT9834C-30
VDS = 2.1V
5V
5
20
4.5V
Output Current (mA)
Reset Threshold Deviation (V)
6
4.2V
4
3
2.2V
2
VDS = 1.5V
15
VDS = 1V
10
VDS = 0.5V
5
1.2V
0
1
-50
-25
0
25
50
75
100
0
125
1
2
Temperature (°C)
Power-Up Reset Timeout (ms)
Power-Up Reset Timeout (ms)
400
VTH = 2.9V
300
VTH = 3V
100
0
6
RT9834A
75
VTH = 5V
50
VTH = 4.5V
25
0
-50
-25
0
25
50
75
100
125
-50
-25
Output Delay Time vs. Load Capacitance
Nch Driver Output Current (mA)
160
100
10
VTH = 3V
1
VTH = 2.9V
VTH = 5V
0.01
0.0001
25
50
75
100
125
Nch Driver Output Current vs. VDS
1000
0.1
0
Temperature (°C)
Temperature (°C)
Output Delay Time (ms)
5
Power-Up Reset Timeout vs. Temperature
100
RT9834C
200
4
Input Voltage (V)
Power-Up Reset Timeout vs. Temperature
500
3
RT9834G-31
140
120
100
VDD = 6V
= 5.5V
= 5V
= 4.5V
= 4V
= 3.5V
80
60
40
20
0
0.0010
0.0100
0.1000
Load Capacitance (µF)
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1.0000
0
1
2
3
4
5
6
VDS (V)
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RT9834
Power-Up Reset Timeout vs. Temperature
Nch Driver Output Current vs. Input Voltage
500
RT9834G-31
VDS = 0.5V
Power-Up Reset Timeout (ms)
Nch Driver Output Current (mA)1
60
−30°C
50
25°C
40
80°C
30
20
10
RT9834G-31
400
300
200
100
0
0
0
1
2
3
4
5
-50
6
-25
0
75
100
125
Power-Down Reset Delay vs. Temperature
Output Voltage vs. Input Voltage
30
Power-Down Reset Delay (µs)
RT9834G-31
6
Output Voltage (V)
50
Temperature (°C)
Input Voltage (V)
7
25
5
4
3
2
1
RT9834G-31
25
20
VDROP = 200mV
VDROP = 150mV
15
10
VDROP = 250mV
5
0
0
0
1
2
3
4
5
Input Voltage (V)
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10
6
-50
-25
0
25
50
75
100
125
Temperature (°C)
is a registered trademark of Richtek Technology Corporation.
DS9834-00 May 2013
RT9834
Application Information
Most μP supervisor ICs have reset threshold voltages
between 1% and 1.5% below the value of nominal supply
voltages. This ensures a reset will not occur within 1% of
the nominal supply, but will occur when the supply is 1.5%
below nominal.
Thermal Considerations
For continuous operation, do not exceed absolute
maximum junction temperature. The maximum power
dissipation depends on the thermal resistance of the IC
package, PCB layout, rate of surrounding airflow, and
difference between junction and ambient temperature. The
maximum power dissipation can be calculated by the
following formula :
0.6
Maximum Power Dissipation (W)
Benefits of Highly Accurate Reset Threshold
Four-Layer PCB
0.5
SOT-143
0.4
0.3
SC-82
0.2
0.1
0.0
0
25
50
75
100
125
Ambient Temperature (°C)
Figure 1. Derating Curve of Maximum Power Dissipation
PD(MAX) = (TJ(MAX) − TA) / θJA
where TJ(MAX) is the maximum junction temperature, TA is
the ambient temperature, and θJA is the junction to ambient
thermal resistance.
For recommended operating condition specifications, the
maximum junction temperature is 125°C. The junction to
ambient thermal resistance, θJA, is layout dependent. For
SOT-143 package, the thermal resistance, θJA, is 228.1°C/
W on a standard JEDEC 51-7 four-layer thermal test board.
SC-82 package, the thermal resistance, θJA, is 345.6°C/
W on a standard JEDEC 51-7 four-layer thermal test board.
The maximum power dissipation at TA = 25°C can be
calculated by the following formula :
PD(MAX) = (125°C − 25°C) / (228.1°C/W) = 0.44W for
SOT-143 package
PD(MAX) = (125°C − 25°C) / (345.6°C/W) = 0.29W for
SC-82 package
The maximum power dissipation depends on the operating
ambient temperature for fixed T J(MAX) and thermal
resistance, θJA. The derating curve in Figure 1 allows the
designer to see the effect of rising ambient temperature
on the maximum power dissipation.
Copyright © 2013 Richtek Technology Corporation. All rights reserved.
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RT9834
Outline Dimension
D
e
H
L
B
C
b
b1
A
A1
e
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
0.800
1.200
0.031
0.047
A1
0.050
0.150
0.002
0.006
B
1.200
1.400
0.047
0.055
b
0.300
0.520
0.012
0.020
b1
0.760
0.920
0.030
0.036
C
2.100
2.640
0.083
0.104
D
2.800
3.040
0.110
0.120
e
1.900
0.075
H
0.080
0.150
0.003
0.006
L
0.210
0.410
0.008
0.016
SOT-143 Surface Mount Package
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is a registered trademark of Richtek Technology Corporation.
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RT9834
D
e
H
L
B
C
b1
b
A
A1
e
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
0.800
1.100
0.031
0.043
A1
0.000
0.100
0.000
0.004
B
1.150
1.350
0.045
0.053
b
0.150
0.400
0.006
0.016
b1
0.350
0.500
0.014
0.020
C
1.800
2.450
0.071
0.096
D
1.800
2.200
0.071
0.087
e
1.300
0.051
H
0.080
0.260
0.003
0.010
L
0.200
0.460
0.008
0.018
SC-82 Surface Mount Package
Richtek Technology Corporation
5F, No. 20, Taiyuen Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789
Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should
obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot
assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be
accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.
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