ETC RT9802A

RT9802
Preliminary
User Programmable Micro-Power Voltage Detectors
General Description
Features
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 VTH is easily achieved through 3 pins
connected to GND, VDD or floating for different
threshold voltage settings. Two versions of threshold
voltages, 1.5V ~ 4V and 2.5V ~ 5V, which are
programmed in factory are offered by customer
demands.
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Applications
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The RT9802 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.
Reset signal will release after VDD is recovered and
lasts for the whole period of Reset Active Time-out
period.
User Programmable Threshold 1.5V to 5V in
0.1V Step with ±3% Accuracy
Low Supply Current 3µA
Quick Reset within 20µS
Built-in Recovery Delay 200mS
Low Functional Supply Voltage 0.9V
Small SOT-26 Package
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Computers
Controllers
Intelligent Instruments
Critical µP and µC Power Monitoring
Portable/Battery-Powered Equipment
Pin Configurations
Part Number
RT9802…CE
(Plastic SOT-26)
RT9802 is CMOS, active-low output and provided in
SOT-26 package.
Pin Configurations
TOP VIEW
6
5
4
1
2
3
1.
2.
3.
4.
5.
6.
VSET0
GND
RESET
VDD
VSET2
VSET1
Ordering Information
RT9802… … …
Typical Application Circuit
Package Type
E : SOT-26
Operating temperature range
C: Commercial standard
Reset Threshold
A : 2.5V~5V
B : 1.5V~4V
VSET0 VSET1
µP
GND
RT9802
GND
VSET2
VDD
RESET
RESET
VDD
RT9802B VTH = 2.5V in this example
DS9802-00 January 2002
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RT9802
Preliminary
Pin Description
Pin Name
Pin Function
VSET0
Threshold Voltage Selection Pin 1
GND
Ground Pin
RESET
Reset Pulse Output, Negative Pulse
VDD
Power Pin
VSET1
Threshold Voltage Selection Pin 2
VSET2
Threshold Voltage Selection Pin 3
Function Block Diagram
Internal Clock
VDD
VDD
P
VSET0
VSET1
VSET
CMP
TIMER
RESET
N
VSET2
Threshold Voltage Setting
POR
Power On Reset
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DS9802-00 January 2002
RT9802
Preliminary
Absolute Maximum Ratings
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Terminal Voltage (with Respect to GND)
VDD
All Other Inputs
Input Current, VDD
Continuous Power Dissipation, PD @ TA = 25°C
SOT-26
Operating Junction Temperature Range
Storage Temperature Range
Package Thermal Resistance
SOT-26, θJA
Lead Temperature (Soldering, 5sec.)
-0.3V to 6.0V
-0.3V to VDD+0.3V
20mA
0.25W
-40°C ~ 125°C
-65°C ~ 125°C
250°C /W
260°C
Electrical Characteristics
(VDD = 3.0, unless specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
0.9
--
6
V
Operating VDD (VOUT) Range
VDD
Supply Current
IDD
VDD = 1.5V ~ 3.5V, IOUT = 0
VDD = 3.5V ~ 5V, IOUT = 0
--
Reset Threshold
VTH
TA = 27°C
--
Threshold Voltage Accuracy
∆VTH
TA = 27°C
--
VCC Drop to Reset Delay
tRD
Drop = -125mV
--
Reset Active Time Out Period
tRP
VDD ≥ 1.02×VTH,
Programmable
VIL
DS9802-00 January 2002
3.3
Note1
µA
--
V
3
%
--
20
µS
--
200
--
mS
TA = 27°C
--
0.2VDD
--
VIH
TA = 27°C
--
0.85VDD
--
VOL
VDD < VTH, ISINK = 3.5mA
--
0.4
--
VSET Pin Input Threshold
RESET Output Voltage
3
V
V
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RT9802
Preliminary
Note 1: Pin Conditions for Programmable Threshold Voltage Setting
RT9802A
RT9802B
VSET0 input
VSET1 input
VSET2 input
5
4
VDD
VDD
VDD
4.9
3.9
VDD
VDD
floating
4.8
3.8
VDD
VDD
GND
4.7
3.7
VDD
floating
VDD
4.6
3.6
VDD
floating
floating
4.5
3.5
VDD
floating
GND
4.4
3.4
VDD
GND
VDD
4.3
3.3
VDD
GND
floating
4.2
3.2
VDD
GND
GND
4.1
3.1
floating
VDD
VDD
4
3
floating
VDD
floating
3.9
2.9
floating
VDD
GND
3.8
2.8
floating
floating
VDD
3.7
2.7
floating
floating
floating
3.6
2.6
floating
floating
GND
3.5
2.5
floating
GND
VDD
3.4
2.4
floating
GND
floating
3.3
2.3
floating
GND
GND
3.2
2.2
GND
VDD
VDD
3.1
2.1
GND
VDD
floating
3
2
GND
VDD
GND
2.9
1.9
GND
floating
VDD
2.8
1.8
GND
floating
floating
2.7
1.7
GND
floating
GND
2.6
1.6
GND
GND
VDD
2.5
1.5
GND
GND
floating
VDD: bond to VDD; 0: bond to GND; f: no bonding
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DS9802-00 January 2002
RT9802
Preliminary
Package Information
D
C
B
b
H
A
A1
e
Symbol
L
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
0.889
1.295
0.035
0.051
A1
--
0.152
--
0.006
B
1.397
1.803
0.055
0.071
b
0.356
0.559
0.014
0.022
C
2.591
2.997
0.102
0.118
D
2.692
3.099
0.106
0.122
e
0.838
1.041
0.033
0.041
H
0.102
0.254
0.004
0.010
L
0.356
0.610
0.014
0.024
SOT- 26 Surface Mount Package
DS9802-00 January 2002
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RT9802
Preliminary
RICHTEK TECHNOLOGY CORP.
RICHTEK TECHNOLOGY CORP.
Headquarter
Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City
8F-1, No. 137, Lane 235, Paochiao Road, Hsintien City
Hsinchu, Taiwan, R.O.C.
Taipei County, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Tel: (8862)89191466 Fax: (8862)89191465
Email: [email protected]
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DS9802-00 January 2002