IMP18 1 1
P
OWER
M
ANAGEMENT
Low Power, 5V µP Reset
Key Features
x
Improved Dallas DS1811 replacement
— 50% lower maximum supply current
x
Low Supply Current
— 20µA maximum (5.5V)
x
Automatically restarts a microprocessor after
power failure
x
150ms reset delay after V
CC
returns to an
in-tolerance condition
x
Active LOW power-up reset
x
Precision temperature-compensated voltage
reference and comparator
x
Eliminates external components
x
Low-cost TO-92 package
x
Compact surface mount SOT-23 package
x
Operating temperature – 40°C to +85°C
– Active LOW, Open-Drain Output
The IMP1811 supply voltage monitor is an improved, low-power
replacement for the Dallas Semiconductor DS1811. Maximum supply
current over temperature is a low 20µA, representing 50 percent lower
power as compared to the DS1811.
The IMP1811 issues an active LOW reset signal whenever the monitored
supply is out-of-tolerance. A precision reference and comparator circuit
monitor power supply (V
CC
) level. Tolerance level options are 5-, 10- and
15-percent. 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 150ms to allow the power supply and system microprocessor
to stabilize.
The IMP1811 is designed with a open-drain output stage and operates
over the extended industrial temperature range. Devices are available in
compact surface mount SOT-23 packages and 3-lead TO-92 packages.
Other low power products in this family include the IMP1810/12/15/16/17,
IMP1233D and IMP1233M.
Family Selection Guide
Part
IMP1810
IMP1811
IMP1812
IMP1815
IMP1816
IMP1817
IMP1233D
IMP1233M
Applications
Output
Stage
Push-Pull
Open-Drain
Push-Pull
Push-Pull
Open-Drain
Push-Pull
Open-Drain
Open-Drain
RESET Voltage RESET Time
(V)
(ms)
4.620, 4.370, 4.120
4.620, 4.350, 4.130
4.620, 4.350, 4.130
3.060, 2.880, 2.550
3.060, 2.880, 2.550
3.060, 2.880, 2.550
4.625, 4.375, 4.125
4.625, 4.375, 2.720
150
150
150
150
150
150
350
350
RESET
Polarity
LOW
LOW
HIGH
LOW
LOW
HIGH
LOW
LOW
x
x
x
x
x
x
x
Set-top boxes
Cellular phones
PDAs
Energy management systems
Embedded control systems
Printers
Single board computers
Block Diagram
V
CC
1
VCC
Supply
Tolerance
Bias
Typical Application
IMP1811
+
–
Delay
150ms Typical
5.5kΩ
2
IMP1811
RESET
RESET
Microprocessor
RESET
Reference
3
GND
©
1999 IMP, Inc.
GND
1811_02.eps
1811_01.eps
408-432-9100/www.impweb.com
1
A1PROS [ A1 PROS CO., LTD. ]
