ASM1233D-L/D/M
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 1.3
Low Power, 5V/3.3V, P Reset, Active LOW, Open-Drain Output
March 2005
General Description
The ASM1233D-L/1233D/1233M are voltage supervisors with
low-power, 5/3.3V P Reset, with an active LOW, open-drain
output. Maximum supply current over temperature is 15A for
3.3V devices and 20A for 5V devices.
The ASM1233D-L/1233D/1233M generates an active LOW
reset signal whenever the monitored supply is out of tolerance.
A precision reference and comparator circuit monitors power
supply (V
CC
) level. The tolerance are 5%,10% and 15%. When
an out-of-tolerance condition is detected, an internal power-fail
signal is generated which forces an active LOW reset signal.
After V
CC
returns to an in-tolerance condition, the reset signal
remains active for 350ms to allow the power supply and system
microprocessor to stabilize.
The ASM1233D-L/1233D/1233M is designed with an open-
drain output stage and operates over the extended industrial
temperature range. These devices are available in compact
SOT-223, SO-8 and TO-92 packages.
Other low power products in this family include ASM1810/11/
12/15/16/17.
Key Features
Low Supply Current
15A maximum (<=3.6V), 20A maximum (5.5V)
Automatically restarts a microprocessor after power failure
350ms reset delay after V
CC
returns to an in-tolerance con-
dition
Active LOW power-up reset, 5k
internal pull-up
Precision temperature-compensated voltage reference and
comparator
Eliminates external components
Low-cost SOT-223/SO-8/TO-92 packages
Operating temperature: -40C to +85C
Applications
Set-top boxes
Cellular phones
PDAs
Energy management systems
Embedded control systems
Printers
Single board computers
Typical Operating Circuit
Block Diagram
Microprocessor
V
CC
RESET
RESET
GND
ASM1
233D-L/D/
M
GND
Supply
Reference
Delay
350ms
Typical
Tolerance
Bias
+
-
ASM1233D-L,ASM1233D,ASM1233M
V
CC
RESET
Delay
Typical
+
-
5.0k
3 of 11
Notice: The information in this document is subject to change without notice
Low Power, 5V/3.3V, P Reset, Active LOW, Open-Drain Output
ASM1233D-L/D/M
rev 1.3
March 2005
Application Information
Operation - Power Monitor
The ASM1233D-L/1233D/1233M detects out-of-tolerance
power supply conditions. It resets a processor during power-
up, power-down and generates a reset to the system
processor when the monitored power supply voltage is below
the reset threshold. When an out-of-tolerance V
CC
voltage is
detected, the RESET signal is asserted. On power-up,
RESET is kept active (LOW) for approximately 350ms after
the power supply voltage has reached the selected tolerance.
This allows the power supply and microprocessor to stabilize
before RESET is released.
~~
t
RPU
V
LTL
~~
V
OH
V
CCTP
V
HTL
t
R
V
CC
RESET
Figure 1: Timing Diagram: Power-Up
~ ~
V
LTL
V
CCTP
V
HTL
t
F
V
CC
t
RPD
V
OL
RESET
Figure 2: Timing Diagram: Power-Down
ASM1233D-L/D/M
4 of 11
Notice: The information in this document is subject to change without notice
Low Power, 5V/3.3V, P Reset, Active LOW, Open-Drain Output
rev 1.3
March 2005
Absolute Maximum Ratings
Parameter
Min
Max
Unit
Voltage on V
CC
-0.5
7
V
Voltage on RESET
-0.5
V
CC
+ 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 ratings for prolonged
periods of time may affect device reliability.
ASM1233D-L/D/M
5 of 11
Notice: The information in this document is subject to change without notice
Low Power, 5V/3.3V, P Reset, Active LOW, Open-Drain Output
rev 1.3
March 2005
Electrical Characteristics
Unless otherwise noted, V
CC
= 5V+10% and specifications are over the operating temperature range of -40C to +85C.
All voltages are referenced to ground.
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Supply Voltage
V
CC
1.2
5.5
V
Output Voltage
V
OL
RESET asserted
-
-
0.4
V
V
OH
I
OUT
< 500 A
V
CC
-0.5V
V
CC
-0.1V
Output Current
I
OL
Output = 0.4V
8
mA
Operating Current
I
CC
V
CC
< 5.5V, RESET output open
8
20
A
V
CC
< =3.6V, RESET output open
6
15
V
CC
Trip Point
V
CCTP
ASM1233D-LZ-5
2.98
3.06
3.15
V
ASM1233D-LZ-10
2.8
2.88
2.97
ASM1233D-LZ-15
2.64
2.72
2.8
ASM1233DZ-5
4.5
4.625
4.74
ASM1233DZ-10
4.25
4.375
4.49
ASM1233DZ-15
4.0
4.125
4.24
ASM1233M-5
4.25
4.375
4.49
ASM1233M-55
4.5
4.625
4.75
ASM1233M-3
2.64
2.72
2.8
Voltage High Trip Level
V
HTL
ASM1233D, ASM1233MS-5,
ASM1233MS-55
4.75
V
ASM1233MS-3
3.14
ASM1233D-L
3.06
Voltage Low Trip Level
V
LTL
ASM1233D, ASM1233MS-5,
ASM1233MS-55
4.00
V
ASM1233MS-3
2.48
ASM1233D-L
2.3
Internal Pull-up Resistor
R
P
3.5
5.0
7.5
k
Output Capacitance
C
OUT
10
pF
V
CC
Detect to RESET Low
t
RPD
2
10
s
V
CC
Detect to RESET High
t
RPU
ASM1233D-L, ASM1233M
200
350
500
ms
ASM1233D
250
350
450
V
CC
Slew Rate
(V
HTL
- V
LTL
)
t
F
300
s
V
CC
Slew Rate
(V
LTL
- V
HTL
)
t
R
0
ns
Note: A 1k
resistor maybe required in some applications for proper operation of the microprocessor reset control circuit.
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