Preliminary
RT9802
User Programmable Micro-Power Voltage Detectors
General Description
The RT9802 is a micro-power voltage detector
supervising the power supply voltage level for
microprocessors (μP) or digital systems. It provides user
programmable threshold levels with 0.1V step ranging
from 1.5V to 5V, which covers most digital applications. It
features low supply current of 3μA. Selection of V
TH
is
easily achieved through 3 pins connected to GND, V
DD
or
floating for different threshold voltage settings. Two versions
of threshold voltages, 1.5V to 4V and 2.5V to 5V, which
are programmed in factory are offered by customer
demands.
The RT9802 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. Reset signal will release after V
DD
is recovered and lasts for the whole period of Reset Active
Time-out period.
RT9802 is CMOS, active-low output and provided in
SOT-23-6 package.
Features
User Programmable Threshold 1.5V to 5V in 0.1V
Step with ± 3% Accuracy
Low Supply Current 3μA
μ
Quick Reset within 20μs
μ
Built-in Recovery Delay 200ms
Low Functional Supply Voltage 0.9V
Small
SOT-23-6
Package
RoHS Compliant and 100% Lead (Pb)-Free
Applications
Computers
Controllers
Intelligent Instruments
Critical
μP
and
μC
Power Monitoring
Portable/Battery-Powered Equipment
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.
Ordering Information
RT9802
-
Package Type
E : SOT-23-6
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
Reset Threshold
A : 2.5V to 5V
B : 1.5V to 4V
Pin Configurations
(TOP VIEW)
VSET1 VSET2 VDD
6
1
5
2
4
3
VSET0 GND RESET
SOT-23-6
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.
Note
: There is no pin1 indicator on top mark for SOT-23-6
type, and pin 1 will be lower left pin when reading top mark
from
left to right.
DS9802-07 March 2007
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1
RT9802
Typical Application Circuit
Preliminary
μP
VDD
GND
RESET
VSET0
VSET1
RT9802
GND
VSET2
RESET
VDD
RT9802B V
TH
= 2.5V in this example
Functional Pin Description
Pin Name
VSET0
GND
RESET
VDD
VSET1
VSET2
Pin Function
Threshold Voltage Selection Pin 1
Ground Pin
Reset Pulse Output, Negative Pulse
Power Pin
Threshold Voltage Selection Pin 2
Threshold Voltage Selection Pin 3
Function Block Diagram
VDD
Internal Clock
VSET0
VSET1
VSET2
P MOS
VSET
CMP
Timer
N MOS
Threshold Voltage Setting
GND
POR
Power On Reset
RESET
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DS9802-07 March 2007
Preliminary
Absolute Maximum Ratings
RT9802
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, V
DD
----------------------------------------------------------------------------------------------------- 20mA
Continuous Power Dissipation, P
D
@ T
A
= 25°C
SOT-23-6 ----------------------------------------------------------------------------------------------------------------
0.25W
Operating Junction Temperature Range --------------------------------------------------------------------------
−
40°C to 125°C
Storage Temperature Range ----------------------------------------------------------------------------------------
−
65°C to 125°C
Package Thermal Resistance
SOT-23-6,
θ
JA
----------------------------------------------------------------------------------------------------------- 250°C /W
Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260°C
Electrical Characteristics
(V
DD
= 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
VSET Pin Input Threshold
RESET Output Voltage
Symbol
V
DD
I
DD
V
TH
ΔV
TH
t
RD
t
RP
V
IL
V
IH
V
OL
Test Conditions
Min
0.9
Typ
--
Max
6
3
3.3
Units
V
μA
V
%
μs
ms
V
V
V
DD
= 1.5V ~ 3.5V, I
OUT
= 0
V
DD
= 3.5V ~ 5V, I
OUT
= 0
T
A
= 27°C
T
A
= 27°C
Drop = -125mV
V
DD
≥
1.02×V
TH
, Programmable
T
A
= 27°C
T
A
= 27°C
V
DD
< V
TH
, I
SINK
= 3.5mA
--
--
--
--
--
--
--
--
Note1
--
3
--
200
0.2V
DD
0.85V
DD
0.4
20
--
--
--
--
DS9802-07 March 2007
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3
RT9802
RT9802A
5
4.9
4.8
4.7
4.6
4.5
4.4
4.3
4.2
4.1
4
3.9
3.8
3.7
3.6
3.5
3.4
3.3
3.2
3.1
3
2.9
2.8
2.7
2.6
2.5
RT9802B
4
3.9
3.8
3.7
3.6
3.5
3.4
3.3
3.2
3.1
3
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2
1.9
1.8
1.7
1.6
1.5
Preliminary
Note 1: Pin Conditions for Programmable Threshold Voltage Setting
VSET0 input
V
DD
V
DD
V
DD
V
DD
V
DD
V
DD
V
DD
V
DD
V
DD
floating
floating
floating
floating
floating
floating
floating
floating
floating
GND
GND
GND
GND
GND
GND
GND
GND
VSET1 input
V
DD
V
DD
V
DD
floating
floating
floating
GND
GND
GND
V
DD
V
DD
V
DD
floating
floating
floating
GND
GND
GND
V
DD
V
DD
V
DD
floating
floating
floating
GND
GND
VSET2 input
V
DD
floating
GND
V
DD
floating
GND
V
DD
floating
GND
V
DD
floating
GND
V
DD
floating
GND
V
DD
floating
GND
V
DD
floating
GND
V
DD
floating
GND
V
DD
floating
V
DD
: bond to V
DD
; 0: bond to GND; f: no bonding
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DS9802-07 March 2007
Preliminary
Outline Dimension
RT9802
H
D
L
C
B
b
A
A1
e
Symbol
A
A1
B
b
C
D
e
H
L
Dimensions In Millimeters
Min
0.889
0.000
1.397
0.250
2.591
2.692
0.838
0.080
0.300
Max
1.295
0.152
1.803
0.560
2.997
3.099
1.041
0.254
0.610
Dimensions In Inches
Min
0.031
0.000
0.055
0.010
0.102
0.106
0.033
0.003
0.012
Max
0.051
0.006
0.071
0.022
0.118
0.122
0.041
0.010
0.024
SOT-23-6
Surface Mount Package
Richtek Technology Corporation
Headquarter
5F, No. 20, Taiyuen Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Richtek Technology Corporation
Taipei Office (Marketing)
8F, No. 137, Lane 235, Paochiao Road, Hsintien City
Taipei County, Taiwan, R.O.C.
Tel: (8862)89191466 Fax: (8862)89191465
Email: marketing@richtek.com
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