ALSC ASM8500

ASM8500
November 2003
rev 1.0
Low Power 5V / 3.3V µP Reset Active LOW, Open - Drain Output
General Description
The ASM8500 is a voltage supervisory device with a low-power,
5V/3.3V µP Reset, active LOW, open-drain output. Maximum
supply current over temperature is a low 6µA.
•
Printers
•
Single board computers
Typical Operating Circuit
The ASM8500 generates an active LOW reset signal whenever
VCC
the monitored supply is out of tolerance. A precision reference
and comparator circuit monitor power supply (VCC) level. Reset
ASM8500
threshold tolerance level is ±1.5%. When an out-of-tolerance
condition is detected, an internal power-fail signal is generated
Microprocessor
which forces an active LOW reset signal. After VCC returns to
an in-tolerance condition, the reset signal remains active for
RESET
RESET
1.5ms to allow the power supply and system microprocessor to
stabilize.
GND
The ASM8500 is designed with a open-drain output stage and
operates over the extended industrial temperature range.
Devices are available in compact surface mount SOT-89
Block Diagram
packages.
Other low power products in this family include the ASM1810/
VCC
11/12/15/16/17, ASM1233D and ASM1233M.
ASM8500
Supply
Tolerance
Bias
Key Features
5ΚΩ
RESET
•
Low Supply Current
+
• 6 µA maximum (5.5 V)
•
Automatically restarts a microprocessor after power failure
-
•
1.5ms reset delay after VCC returns to an in-tolerance con-
•
Active LOW power-up reset
•
Precision temperature-compensated voltage reference and
Delay
1.5ms
Typical
Reference
dition
comparator
•
Eliminates external components
•
Compact surface mount SOT-89 package
•
Operating temperature -40°C to +85°C
GND
Applications
•
Set-top boxes
•
Cellular phones
•
PDAs
•
Energy management systems
•
Embedded control systems
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
ASM8500
November 2003
rev 1.0
Pin Configuration
1
VCC
2
GND
3
RESET
Pin Description
Pin #
Pin Name
Description
1
VCC
Power supply input
2
GND
Ground
3
RESET
Active LOW reset output
Low Power 5V / 3.3V µP Reset Active LOW, Open - Drain Output
Notice: The information in this document is subject to change without notice
2 of 7
ASM8500
November 2003
rev 1.0
Application Information
Operation - Power Monitor
The
ASM8500
detects
out-of-tolerance
power
supply
conditions. It resets a processor during power-up, power-
tF
VCC
VCCTP (MAX)
down and issues a reset to the system processor when the
VCCTP
monitored power supply voltage is below the reset threshold.
VCCTP (MIN)
When an out-of-tolerance VCC voltage is detected, the
voltage has reached the selected tolerance. This allows the
RESET
tRPD
~
~
RESET signal is asserted. On power-up, RESET is kept
active (LOW) for approximately 1.5ms after the power supply
power supply and microprocessor to stabilize before RESET
is released.
VOL
tR
VCCTP (MAX)
VCCTP (MIN)
~
VCC
Figure 2: Timing Diagram: Power-Down
VCCTP
tRPU
VOH
~
RESET
Figure 1: Timing Diagram: Power-Up
Low Power 5V / 3.3V µP Reset Active LOW, Open - Drain Output
Notice: The information in this document is subject to change without notice
3 of 7
ASM8500
November 2003
rev 1.0
Absolute Maximum Ratings
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
260
°C
125
°C
Soldering Temperature (for 10 sec)
Storage Temperature
-55
NOTE: These are stress ratings only and functional use is not implied. Exposure to absolute maximum ratings for prolonged periods of time may affect device reliability.
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
Symbol
Conditions
Supply Voltage
VCC
Output Voltage
VOH
IOUT < 500 µA
Output Current
IOH
Output = 0.4V, VCC > 2.7V
Operating Current
ICC
Min
Typ
1
VCC - 0.5V
Max
Unit
5.5
V
VCC - 0.1V
V
+10
VCC < 5.5V, RESET output
open
mA
6
µA
VCC Trip Point (ASM8500-42)
VCCTP
4.2
V
VCC Trip Point (ASM8500-29)
VCCTP
2.9
V
VCC Trip Point (ASM8500-27)
VCCTP
2.7
V
RP
Internal Pull-up Resistor
Output Capacitance
COUT
RESET Active Time
tRESET
VCC Detect to RESET Low
0.5
tRPD
VCC Slew Rate
(VCCTP (MAX) to VCCTP (MIN)
VCC Slew Rate
(VCCTP (MIN) to VCCTP (MAX)
VCC Detect to RESET High
3.5
5.5
7.5
kΩ
10
pF
1.5
5
ms
2
5
µs
tF
300
µs
tR
0
ns
tRPU
tr = 5µs
0.5
1.5
5
ms
Note: The tF value is for reference in defining values for tRPD and should not be considered for proper operation or use.
Low Power 5V / 3.3V µP Reset Active LOW, Open - Drain Output
Notice: The information in this document is subject to change without notice
4 of 7
ASM8500
November 2003
rev 1.0
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
ASM8500
4.2, 2.9, 2.7
1.5
Open-Drain
LOW
Low Power 5V / 3.3V µP Reset Active LOW, Open - Drain Output
Notice: The information in this document is subject to change without notice
5 of 7
ASM8500
November 2003
rev 1.0
Package Dimensions
Plastic SOT-89
D
D1
H
Polish
E
HE
A1
S1
e
b
b1
C
Matte Finish
b
Polish
Dimension in Millimeters
Dimensions in Inches
Symbol
Min
Max
Min
Max
A
1.40
1.60
0.0551
0.0630
A1
0.89
-
0.0350
-
b
0.36
0.52
0.0142
0.0205
b1
0.41
0.56
0.0161
0.0220
C
0.35
0.44
0.0138
0.0173
D
4.40
4.60
0.1732
0.1811
D1
1.35
1.83
0.0531
0.0720
HE
-
4.25
-
0.1673
E
2.29
2.60
0.0902
0.1024
e
2.90
3.10
0.1142
0.1220
H
0.35
0.70
0.0138
0.0276
S1
1.40
1.60
0.0551
0.0630
Low Power 5V / 3.3V µP Reset Active LOW, Open - Drain Output
Notice: The information in this document is subject to change without notice
6 of 7
ASM8500
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
Preliminary Information
Part Number: ASM8500
Document Version: 1.0
© Copyright 2003 Alliance Semiconductor Corporation. All rights reserved. Our three-point logo, our name and Intelliwatt are trademarks or
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