RT9817
Micro-Power Voltage Detectors with Manual Reset
General Description
The RT9817 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 RT9817 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. To pull reset signal
low manually, just pull the manual reset input (MR) below
the specified V
IL
level. RT9817 is provided
in SC-82 and
SOT-143 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
Quick Reset within 20μs
μ
Built-in Recovery Delay Include 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 100% Lead (Pb)-Free
Applications
Computers
Controllers
Intelligent Instruments
Critical
μP
and
μC
Power Monitoring
Portable/Battery-Powered Equipment
Ordering Information
RT9817
-
Package Type
H : SOT-143
Y : SC-82
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)
Pin Configurations
(TOP VIEW)
VDD
4
1
GND
MR
3
2
RESET/
RESET
VDD
4
1
GND
MR
3
2
RESET/
RESET
SOT-143
SC-82
Note
: There is no pin1 indicator on top mark for SC-82 and
SOT-143 types, and pin 1 will be lower left pin when reading
top mark from left to right. Pin2 of SC-82 and Pin1 of SOT-
143 is wider than other pins in each package.
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.
DS9817-07 August 2007
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1
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.
RT9817
Typical Application Circuit
VDD
up
RESET/
RESET
RT9817
GND
RESET/
RESET
VDD
MR
Functional Pin Description
Pin Name
GND
RESET
RESET
MR
Pin Function
Ground Pin
Active Low Push-Pull Reset Output
Active High Push-Pull Reset Output
Manual Reset
Power Pin
VDD
Function Block Diagram
VDD
MR
VDD
P MOS
VSET
Threshold
Voltage Setting
POR
Power On Reset
CMP
Timer
N MOS
RESET/
RESET
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DS9817-07 August 2007
RT9817
Absolute Maximum Ratings
(Note 1)
Terminal Voltage (with Respect to GND)
V
DD
------------------------------------------------------------------------------------------------------------------------
−
0.3V to 6.0V
All Other Inputs --------------------------------------------------------------------------------------------------------
−
0.3V to V
DD
+0.3V
Input Current, I
VDD
----------------------------------------------------------------------------------------------------- 20mA
Power Dissipation, PD @ T
A
= 25°C
SC-82 --------------------------------------------------------------------------------------------------------------------
0.25W
SOT-143 ----------------------------------------------------------------------------------------------------------------- 0.285W
Package Thermal Resistance (Note 4)
SC-82,
θ
JA
--------------------------------------------------------------------------------------------------------------- 400°C
SOT-143,
θ
JA
------------------------------------------------------------------------------------------------------------ 350°C
Lead Temperature (Soldering, 10sec.) ---------------------------------------------------------------------------- 260°C
Storage Temperature Range ----------------------------------------------------------------------------------------
−
65°C to 125°C
ESD Susceptibility (Note 2)
HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 2kV
MM (Machine Mode) -------------------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions
(Note 3)
Junction Temperature Range ----------------------------------------------------------------------------------------
−
40°C to 125°C
Ambient Temperature Range ----------------------------------------------------------------------------------------
−
40°C to 85°C
Electrical Characteristics
(V
DD
= 3V, T
A
= 25°C, unless otherwise specified)
Parameter
Operating V
DD
(V
OUT
) Range
Supply Current
Reset Threshold
Threshold Voltage Accuracy
Threshold Voltage Hysteresis
V
DD
Drop to Reset Delay
RT9817A/E
Reset Active
Time Out Period
RT9817B/F
RT9817C/G
RT9817D/H
Symbol
V
DD
I
DD
V
TH
ΔV
TH
V
HYS
t
RD
Test Conditions
RT9817A/B/C/D
RT9817E/F/G/H
V
TH
= 3V , V
DD
= 4.5V
Min
0.9
1.1
--
--
−1.5
--
Typ
--
--
3
1.2 to 5.0
--
0.01 V
TH
20
0
55
220
450
--
--
--
Max
6
6
8
--
+1.5
--
--
--
75
297
608
0.4
0.3
0.3
Units
V
μA
V
%
V
μs
ms
ms
ms
ms
Drop = V
TH
−125mV
--
--
t
RP
V
DD
≥
1.02
×
V
TH
35
143
292
V
DD
< V
TH(MIN)
,I
SINK
= 3.5mA,
V
TH
≥
3V
RESET Output Voltage Low
V
OL
V
DD
< V
TH(MIN)
,I
SINK
= 1.2mA,
V
TH
≥
1.8V
V
TH(MIN)
> V
DD
> 1V,
I
SINK
= 0.5mA
--
--
--
V
To be continued
DS9817-07 August 2007
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RT9817
Parameter
Symbol
Test Conditions
V
DD
> V
TH(MAX)
,
I
S OURCE
= 800μA, V
TH
≥
3V
RESET Output Voltage High
V
OH
V
DD
> V
TH(MAX)
,
I
S OURCE
= 500μA, V
TH
≥
1.8V
V
DD
> V
TH(MAX)
,
I
S OURCE
= 200μA, V
TH
≥
1.1V
V
DD
> V
TH(MAX)
,I
SINK
= 3.5mA,
V
TH
≥
3V
RESET Output Voltage Low
V
OL
V
DD
> V
TH(MAX)
,I
SINK
= 1.2mA,
V
TH
≥
1.8V
V
DD
> V
TH(MAX)
,I
SINK
= 0.5mA,
V
TH
≥
1.2V
1.1V < V
DD
< V
TH(MIN)
,
I
S OURCE
= 200μA
RESET Output Voltage High
V
OH
1.8V < V
DD
< V
TH(MIN)
,
I
S OURCE
= 500μA
3V < V
DD
< V
TH(MIN)
,
I
S OURCE
= 800μA
Min
V
DD
−1.5
0.8 V
DD
0.8 V
DD
--
--
--
0.8 V
DD
0.8 V
DD
V
DD
−1.5
Typ
--
--
--
--
--
--
--
--
--
Max
--
--
--
0.4
0.3
0.3
--
--
--
V
V
V
Units
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.
Devices are ESD sensitive. Handling precaution recommended.
Note 3.
The device is not guaranteed to function outside its operating conditions.
Note 4.
θ
JA
is measured in the natural convection at T
A
= 25°C on a low effective thermal conductivity test board of
JEDEC 51-3 thermal measurement standard.
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DS9817-07 August 2007
RT9817
Typical Operating Characteristics
Nch Driver Output Current vs. V
DS
2.4
2
Nch Driver Output Current vs. V
DS
60
RT9817A-12
V
DD
= 1.1V
RT9817C-30
V
DD
= 2.8V
V
DD
= 2.5V
50
Output Current (mA)
1.6
1.2
Output Current (mA)
40
30
V
DD
= 2.0V
20
10
0
V
DD
= 1.0V
0.8
0.4
0
0
0.3
0.6
0.9
1.2
1.5
V
DD
= 1.5V
0
0.5
1
1.5
2
2.5
3
3.5
V
DS
(V)
V
DS
(V)
Nch Driver Output Current vs. V
DS
120
100
Output Voltage vs. Input Voltage
7
6
RT9817A-45
RT9817A
Output Current (mA)
Output Voltage (V)
80
60
40
20
0
0
1
2
3
4
5
5
4
V
DD
= 4.4V
= 4.0V
= 3.5V
= 3.0V
= 2.5V
= 2.0V
= 1.5V
5.0V
3
2
1
0
0
1
2
3
4
5
6
2.9V
3.0V
V
DS
(V)
Input Voltage (V)
Supply Current vs. Input Voltage
6
5
Supply Current vs. Input Voltage
4
RT9817A-12
RT9817C-30
80°C
25°C
Supply Current IDD (uA)
Supply Current (uA)
80°C
3
4
25°C
3
2
1
0
0
1
2
3
4
5
6
2
-30°C
1
-30°C
0
0
1
2
3
4
5
6
Input Voltage (V)
Input Voltage (V)
DS9817-07 August 2007
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