2000 © IMP, Inc.
408-432-9100/www.impweb.com
1
IMP1
IMP1
233M
233M
P
OWER
M
ANAGEMENT
Key Features
Applications
N Set-top boxes
N Cellular phones
N PDAs
N Energy management systems
N Embedded control systems
N Printers
N Single board computers
N Improved Dallas DS1233M replacement
-- 60% lower maximum supply current
N Low Supply Current
-- 20µA maximum (5.5V)
-- 15µA maximum (3.6V)
N Automatically restarts a microprocessor after
power failure
N 350ms reset delay after V
CC
returns to an
in-tolerance condition
N Active LOW power-up reset, 5k internal pull-up
N Precision temperature-compensated voltage
reference and comparator
N Eliminates external components
N Pin function compatible with the Motorola
MC33064, MC34064, MC33164 and MC34164
N Motorola 68xxx and HC16 compatible
N Compact surface mount SO-8 package
N Operating temperature 40°C to +85°C
Block Diagram
+
1233M_01.eps
V
CC
RESET
GND
5.0k
9
Supply
Tolerance
Bias
IMP1233M
Delay
350ms Typical
Reference
Lo
Lo
w P
w P
o
o
w
w
er
er
, 5V/3.0V
, 5V/3.0V
µ
µ
P R
P R
eset
eset
A
A
ctiv
ctiv
e L
e L
O
O
W
W
, Open-Dr
, Open-Dr
ain Output
ain Output
350ms R
350ms R
eset P
eset P
er
er
iod
iod
The IMP1233M supply voltage monitor is an improved, low-power
replacement for the Dallas Semiconductor DS1233M. Maximum supply
current over temperature is a low 20
µA, representing 60 percent lower
power as compared to the DS1233M.
The IMP1233M issues an active LOW reset signal whenever the moni-
tored supply is out-of-tolerance. A precision reference and comparator
circuit monitor power supply (V
CC
) level. Tolerance level options are
5- and 10-percent for a 5V power supply. The tolerance is 15-percent for
the 3.3V, IMP1233M. 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 micro-
processor to stabilize.
The IMP1233M is designed with a open-drain output stage and operates
over the extended industrial temperature range. Devices are available in
the compact surface mount SO-8 package.
Other low power products in this family include the IMP1810/11/12/15/
16/17 and IMP1233D.
Typical Application
IMP1233M
Microprocessor
RESET
RESET
1233M_02.eps
VCC
GND
t
r
a
P
e
g
a
t
l
o
V
T
E
S
E
R
)
V
(
e
m
i
T
T
E
S
E
R
)
s
m
(
t
u
p
t
u
O
e
g
a
t
S
T
E
S
E
R
y
t
i
r
a
l
o
P
0
1
8
1
P
M
I
0
2
1
.
4
,
0
7
3
.
4
,
0
2
6
.
4
0
5
1
ll
u
P
-
h
s
u
P
W
O
L
1
1
8
1
P
M
I
0
3
1
.
4
,
0
5
3
.
4
,
0
2
6
.
4
0
5
1
n
i
a
r
D
-
n
e
p
O
W
O
L
2
1
8
1
P
M
I
0
3
1
.
4
,
0
5
3
.
4
,
0
2
6
.
4
0
5
1
ll
u
P
-
h
s
u
P
H
G
I
H
5
1
8
1
P
M
I
0
5
5
.
2
,
0
8
8
.
2
,
0
6
0
.
3
0
5
1
ll
u
P
-
h
s
u
P
W
O
L
6
1
8
1
P
M
I
0
5
5
.
2
,
0
8
8
.
2
,
0
6
0
.
3
0
5
1
n
i
a
r
D
-
n
e
p
O
W
O
L
7
1
8
1
P
M
I
0
5
5
.
2
,
0
8
8
.
2
,
0
6
0
.
3
0
5
1
ll
u
P
-
h
s
u
P
H
G
I
H
D
3
3
2
1
P
M
I
5
2
1
.
4
,
5
7
3
.
4
,
5
2
6
.
4
0
5
3
n
i
a
r
D
-
n
e
p
O
W
O
L
M
3
3
2
1
P
M
I
0
2
7
.
2
,
5
7
3
.
4
,
5
2
6
.
4
0
5
3
n
i
a
r
D
-
n
e
p
O
W
O
L
Family Selection Guide
I M P 1
I M P 1
2 3 3 M
2 3 3 M
2000 © IMP, Inc.
Microprocessor Supervisor
3
Notes: 1. A 1k
external resistor maybe required in some applications for proper operation of the microprocessor reset control circuit.
Absolute Maximum Ratings
Electrical Characteristics
Voltage on V
CC
. . . . . . . . . . . . . . . . . . . . . . . . 0.5V to 6.5V
Voltage on RESET . . . . . . . . . . . . . . . . . . . . . 0.5V to V
CC
+ 0.5V
Operating Temperature Range . . . . . . . . . . . 40
°C to 85°C
Soldering Temperature . . . . . . . . . . . . . . . . . . 260
°C for 10 seconds
Storage Temperature . . . . . . . . . . . . . . . . . . . 55
°C to 125°C
Voltages measured with respect to ground.
These are stress ratings only and functional operation is not implied.
Parameter
Symbol
Conditions
Min
Typ
Max
Units
Supply Voltage
V
CC
1.2
5.5
V
Output Voltage
V
OH
I
OUT
< 500
µA
V
CC
0.5V
V
CC
0.1V
V
Output Current
I
OL
Output = 0.4V, V
CC
2.7V
+8
mA
Operating Current
I
CC
V
CC
< 5.5V, RESET output open
8
20
µA
Operating Current
I
CC
V
CC
3.6V, RESET output open
6
15
µA
V
CC
Trip Point (IMP1233M-5)
V
CCTP
4.25
4.375
4.49
V
V
CC
Trip Point (IMP1233M-55)
V
CCTP
4.5
4.625
4.75
V
V
CC
Trip Point (IMP1233M-3)
V
CCTP
2.64
2.72
2.8
V
Voltage High Trip Level
V
HTL
4.75
V
IMP1233M-5
IMP1233M-55
Voltage Low Trip Level
V
LTL
4.00
V
IMP1233M-5
IMP1233M-55
Voltage High Trip Level
V
HTL
3.14
V
IMP1233M-3
Voltage Low Trip Level
V
LTL
2.48
V
IMP1233M-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
µs
V
CC
Slew Rate
t
F
300
µs
(V
HTL
- V
LTL
)
V
CC
Slew Rate
t
R
0
ns
(V
LTL
- V
HTL
)
V
CC
Detect to RESET High
t
RPU
t
R
= 5
µs
200
350
500
ms
Unless otherwise noted, V
CC
= 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.
I M P 1
I M P 1
2 3 3 M
2 3 3 M
4
408-432-9100/www.impweb.com
2000 © IMP, Inc.
!
Operation Power Monitor
The IMP1233M detects out-of-tolerance power supply conditions.
It resets a processor during power-up and issues a reset to the
system processor when the monitored power supply voltage
is below the reset threshold (power-down). 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.
Figure 1. Timing Diagram: Power-Up
Figure 2. Timing Diagram: Power-Down
V
HTL
V
CCTP
V
LTL
V
CC
RESET
t
R
t
RPU
V
OH
1233M_05.eps
V
HTL
V
CCTP
V
LTL
V
CC
RESET
t
F
V
OL
t
RPD
1233M_06.eps
Application Information
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