DS1818
3.3V EconoReset with Pushbutton
www.dalsemi.com
FEATURES
Automatically restarts a microprocessor after
power failure
Monitors pushbutton for external override
Maintains reset for 150 ms after V
CC
returns
to an in-tolerance condition
Reduces need for discrete components
Precision temperature-compensated voltage
reference and voltage sensor
Accurate 5%, 10% or 20% power monitoring
Low-cost TO-92 or space saving surface
mount SOT-23 packages available
Efficient open-drain output with internal
5.5 kΩ=pull-up resistor
Operating temperature -40°C to +85°C
PIN ASSIGNMENT
3
1
2
SOT-23 PACKAGE
1 2 3
1 2 3
TO-92 PACKAGE
See Mech.
Drawings Section
PIN DESCRIPTION
TO-92
1
2
3
RST
V
CC
GND
Active Low Reset Output
Power Supply
Ground
SOT-23
1
2
3
RST
V
CC
GND
Active Low Reset Output
Power Supply
Ground
DESCRIPTION
The DS1818 EconoReset uses a precision temperature-compensated reference and comparator circuit to
monitor the status of the power supply (V
CC
). When an out-of-tolerance condition is detected, an internal
power-fail signal is generated which forces reset to the active state. When V
CC
returns to an in-tolerance
condition, the reset signal is kept in the active state for approximately 150 ms to allow the power supply
and processor to stabilize.
The DS1818 also monitors a pushbutton on the reset output. If the reset line is pulled low, a reset is
generated upon release and the DS1818 output will be held in reset output low for typically 150 ms.
1 of 5
111999
DALLAS [ DALLAS SEMICONDUCTOR ]
