ASM1817
Alliance Semiconductor
2575 Augustine Drive . Santa Clara, CA 95054 . Tel: 408.855.4900 . Fax: 408.855.4999 . www.alsc.com
Notice: The information in this document is subject to change without notice
rev 1.5 Low Power, 3.3V/3.0V µP Reset, Active HIGH, Push-Pull Output
February 2005
General Description
The ASM1817 voltage supervisory device with low-power, 3.3V/
3.0V µP Reset, active HIGH, Push-Pull output. Maximum
supply current over temperature is a low 15µA (at 3.6V).
The ASM1817 generates an active HIGH reset signal whenever
the monitored supply is out of tolerance. A precision reference
and comparator circuit monitor power supply (VCC) level.
Tolerance level options are 5%, 10% and 20% percent. When
an out-of-tolerance condition is detected, an internal power-fail
signal is generated which forces an active HIGH reset signal.
After VCC returns to an in-tolerance condition, the reset signal
remains active for 150ms to allow the power supply and system
microprocessor to stabilize.
The ASM1817 is designed with a push-pull output stage and
operates over the extended industrial temperature range.
Devices are available in TO-92 and compact surface mount
SOT-23 packages.
Other low power products in this family include the ASM1810/
11/12/15/16, ASM1233D and ASM1233M.
Key Features
• Low Supply Current
•20 µA maximum (5.5 V)
•15 µA maximum (3.6 V)
• Automatically restarts a microprocessor after power failure
• 150ms reset delay after VCC returns to an in-tolerance con-
dition
• Active HIGH power-up reset
• Precision temperature-compensated voltage reference and
comparator
• Eliminates external components
• TO-92 and compact surface mount SOT-23 package
• Push-Pull output for minimum current drain
• Operating temperature -40°C to +85°C
Applications
• Set-top boxes
• Cellular phones
•PDAs
• Energy management systems
• Embedded control systems
• Printers
• Single board computers
Typical Operating Circuit
Block Diagram
Microprocessor
VCC
RESET RESET
GND
ASM1817
ASM1817
VCC
Supply
Reference
Delay
150ms
Typical
Tolerance
Bias
+
-
VCC
Supply
Tolerance
Bias
-
GND
RESET
Reference
+
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Notice: The information in this document is subject to change without notice
Low Power, 3.3V/3.0V µP Reset
rev 1.5
February 2005
Pin Configuration
Pin Description
TO-92 SOT-23
Pin Name Description
Pin # Pin #
1 1 RESET Active HIGH reset output
22
VCC Power supply input
3 3 GND Ground
1
2
3
RESET
GND
VCC
ASM1817-R
SOT-23
123
TO-92
ASM1817
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Low Power, 3.3V/3.0V µP Reset
ASM1817
rev 1.5
February 2005
Application Information
Operation - Power Monitor
The ASM1817 detects out-of-tolerance power supply
conditions. It resets a processor during power-up, power-
down and issues a reset to the system processor when the
monitored power supply voltage is below the reset threshold.
When an out-of-tolerance VCC voltage is detected, the
RESET signal is asserted. On power-up, RESET is kept
active (HIGH) for approximatley 150ms after the power
supply voltage has reached the selected tolerance. This
allows the power supply and microprocessor to stablize
before RESET is released.
Figure 1: Typical Application
Microprocessor
RESET RESET
ASM1817
~
~
tRPU
VCCTP (MIN)
~
~
VCCTP
VCCTP (MAX)
tR
VCC
Figure 2: Timing Diagram: Power-Up
VOL
RESET
~
~
~
~
tRPD
VCC VCCTP (MAX)
VCCTP VCCTP (MIN)
tF
RESET
RESET Slews with VCC
VOH
Figure 3: Timing Diagram: Power-Down
ASM1817
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Notice: The information in this document is subject to change without notice
Low Power, 3.3V/3.0V µP Reset
rev 1.5
February 2005
Absolute Maximum Ratings
Electrical Characteristics
Unless otherwise noted, VCC = 1.2V to 5.5V and specifications are over the operating temperature range of -40°C to +85°C. All voltages are referenced to
ground
Parameter Min Max Unit
Voltage on VCC -0.5 7 V
Voltage on RESET -0.5 VCC + 0.5 V
Operating Temperature Range -40 85 °C
Soldering Temperature (for 10 sec) 260 °C
Storage Temperature -55 125 °C
ESD rating
HBM
MM
2
200
KV
V
NOTE: These are stress ratings only and functional use is not implied. Exposure to absolute maximum rat-
ings for prolonged periods of time may affect device reliability.
Parameter Symbol Conditions Min Typ Max Unit
Supply voltage VCC 1.2 5.5 V
Output Voltage VOH IOUT < 500 µA VCC - 0.5V VCC - 0.1V V
Output Current IOH Output = 2.4V, VCC > 2.7V 350 µA
Output Current IOL Output = 0.4V, VCC > 2.7V +10 mA
Operating Current ICC VCC < 5.5V, RESET output open 820µA
Operating Current ICC VCC < 3.6V, RESET output open 615µA
VCC Trip Point (ASM1817R-5) VCCTP 2.98 3.06 3.15 V
VCC Trip Point (ASM1817R-10) VCCTP 2.80 2.88 2.97 V
VCC Trip Point (ASM1817R-20) VCCTP 2.47 2.55 2.64 V
Output Capacitance COUT 10 pF
VCC Detect to RESET Low tRPD 25µs
VCC Slew Rate
(VCCTP (MAX) to VCCTP (MIN) tF300 µs
VCC Slew Rate
(VCCTP (MIN) to VCCTP (MAX) tR0ns
VCC Detect to RESET High tRPU tr = 5µs 100 150 250 ms
Note: The tF value is for reference in defining values for tRPD and should not be considered for proper operation or use.
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Notice: The information in this document is subject to change without notice
Low Power, 3.3V/3.0V µP Reset
rev 1.5
February 2005
Family Selection Guide
Part # RESET Voltage (V) RESET Time
(ms) Output Stage RESET Polarity
ASM1810 4.620, 4.370, 4.120 150 Push-Pull LOW
ASM1811 4.620, 4.350, 4.130 150 Open-Drain LOW
ASM1812 4.620, 4.350, 4.130 150 Push-Pull HIGH
ASM1815 3.060, 2.880, 2.550 150 Push-Pull LOW
ASM1816 3.060, 2.880, 2.550 150 Open-Drain LOW
ASM1817 3.060, 2.880, 2.550 150 Push-Pull HIGH
ASM1233D 4.625, 4.375, 4.125 350 Open-Drain LOW
ASM1233M 4.625, 4.375, 2.720 350 Open-Drain LOW
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Notice: The information in this document is subject to change without notice
Low Power, 3.3V/3.0V µP Reset
ASM1817
rev 1.5
February 2005
Package Dimension
Plastic SOT-23 (3-Pin)
Inches Millimeters
Min Max Min Max
Plastic SOT-23 (3-Pin)
A 0.030 0.046 0.75 1.17
A1 0.002 0.006 0.05 0.15
B 0.012 0.020 0.30 0.50
C 0.003 0.008 0.08 0.20
D 0.110 0.120 2.80 3.04
E 0.047 0.055 1.20 1.40
e 0.037 BSC 0.95 BSC
e1 0.075 BSC 1.9 BSC
H 0.083 0.104 2.10 2.64
L 0.016 0.024 0.40 0.60
a0o8o0o8o
SNA NA
B
EH
Se
D
A
A1 e1 C
L
a
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Notice: The information in this document is subject to change without notice
Low Power, 3.3V/3.0V µP Reset
rev 1.5
February 2005
To-92 (3-Pin)
Dimensions in Inches Dimensions in Millimeters
Min Max Min Max
TO-92
A 0.175 0.185 4.445 4.699
b 0.016 0.020 0.406 0.508
C 0.014 0.016 0.356 0.406
φD 0.175 0.185 4.445 4.699
E 0.138 0.144 3.505 3.658
e 0.098 0.102 2.489 2.591
e1 0.045 0.055 1.143 1.397
j 0.168 0.174 4.269 4.420
L 0.500 0.585 12.7 14.86
s 0.095 0.099 2.413 2.515
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Notice: The information in this document is subject to change without notice
Low Power, 3.3V/3.0V µP Reset
rev 1.5
February 2005
Ordering Information
Device Summary
Part Number**
RESET
Output
Voltage (V)
RESET
Tolerance
(%)
RESET
Time (ms)
Push-Pull
Output Stage
SOT-23
Package
RESET
Polarity
Package
Marking
TIN - LEAD DEVICES
ASM1817R-5 3.06 5 150 HIGH RPLL
ASM1817R-10 2.88 10 150 HIGH RQLL
ASM1817R-20 2.55 20 150 HIGH RRLL
LEAD FREE DEVICES
ASM1817R-5F 3.06 5 150 HIGH KPLL
ASM1817R-10F 2.88 10 150 HIGH KQLL
ASM1817R-20F 2.55 20 150 HIGH KRLL
Part Number**
RESET
Output
Voltage (V)
RESET
Tolerance
(%)
RESET
Time (ms)
Push-Pull
Output Stage
TO-92
Package
RESET
Polarity
Package
Marking
TIN - LEAD DEVICES
ASM1817-5 3.06 5 150 HIGH ASM1817-5
ASM1817-10 2.88 10 150 HIGH ASM1817-10
ASM1817-20 2.55 20 150 HIGH ASM1817-20
LEAD FREE DEVICES
ASM1817-5F 3.06 5 150 HIGH ASM1817-5F
ASM1817-10F 2.88 10 150 HIGH ASM1817-10F
ASM1817-20F 2.55 20 150 HIGH ASM1817-20F
** Add /T to Part Number for Tape and Reel (i.e ASM18xx-x/T)
LL- Lot Code
Alliance Semiconductor Corporation
2575, Augustine Drive,
Santa Clara, CA 95054
Tel: 408 - 855 - 4900
Fax: 408 - 855 - 4999
www.alsc.com
Copyright © Alliance Semiconductor
All Rights Reserved
Part Number: ASM1817
Document Version: 1.5
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ASM1817