19-0344; Rev 4; 12/99
3-Pin Microprocessor Reset Circuits
General Description
The MAX803/MAX809/MAX810 are microprocessor (µP)
supervisory circuits used to monitor the power supplies
in µP and digital systems. They provide excellent circuit
reliability and low cost by eliminating external compo-
nents and adjustments when used with +5V, +3.3V,
+3.0V, or +2.5V-powered circuits.
These circuits perform a single function: they assert a
reset signal whenever the V
CC
supply voltage declines
below a preset threshold, keeping it asserted for at
least 140ms after V
CC
has risen above the reset thresh-
old. Reset thresholds suitable for operation with a vari-
ety of supply voltages are available.
The MAX803 has an open-drain output stage, while the
MAX809/MAX810 have push-pull outputs. The
MAX803’s open-drain
RESET
output requires a pull-up
resistor that can be connected to a voltage higher than
V
CC
. The MAX803/MAX809 have an active-low
RESET
output, while the MAX810 has an active-high RESET
output. The reset comparator is designed to ignore fast
transients on V
CC
, and the outputs are guaranteed to
be in the correct logic state for V
CC
down to 1V.
Low supply current makes the MAX803/MAX809/
MAX810 ideal for use in portable equipment. The
MAX803 is available in a 3-pin SC70 package, and the
MAX809/MAX810 are available in 3-pin SC70 or SOT23
packages.
____________________________Features
o
Precision Monitoring of +2.5V, +3V, +3.3V, and
+5V Power-Supply Voltages
o
Fully Specified Over Temperature
o
Available in Three Output Configurations
Open-Drain
RESET
Output (MAX803)
Push-Pull
RESET
Output (MAX809)
Push-Pull RESET Output (MAX810)
o
140ms min Power-On Reset Pulse Width
o
12µA Supply Current
o
Guaranteed Reset Valid to V
CC
= +1V
o
Power Supply Transient Immunity
o
No External Components
o
3-Pin SC70 and SOT23 Packages
MAX803L/M/R/S/T/Z, MAX809J/L/M/R/S/T/Z, MAX810L/M/R/S/T/Z
Ordering Information
PART
MAX803_EXR-T
MAX803_EXR-T10
MAX809_EXR-T
MAX809_EXR-T10
MAX809_EUR-T
MAX809_EUR-T10
MAX810_EXR-T
MAX810_EXR-T10
MAX810_EUR-T
MAX810_EUR-T10
TEMP. RANGE
-40°C to +105°C
-40°C to +105°C
-40°C to +105°C
-40°C to +105°C
-40°C to +105°C
-40°C to +105°C
-40°C to +105°C
-40°C to +105°C
-40°C to +105°C
-40°C to +105°C
PIN-PACKAGE
3 SC70-3
3 SC70-3
3 SC70-3
3 SC70-3
3 SOT23-3
3 SOT23-3
3 SC70-3
3 SC70-3
3 SOT23-3
3 SOT23-3
Applications
Computers
Controllers
Intelligent Instruments
Critical µP and µC Power Monitoring
Portable/Battery-Powered Equipment
Automotive
Note:
These parts are offered in 2.5k or 10k reels, and must be
ordered in 2.5k or 10k increments. Order MAX803_EXR-T for
2.5k reels and MAX803_EXR-T10 for 10k reels. Insert the
desired suffix letter from the Selector Guide into the blank to
complete the part number. All versions of these products may
not be available at the time of announcement. Contact factory for
availability.
Typical Operating Circuit
TOP VIEW
V
CC
GND
1
V
CC
R
PULL-UP
*
V
CC
Pin Configuration
MAX803
MAX809
RESET
RESET
INPUT
µP
MAX803
MAX809
MAX810
3
V
CC
RESET (RESET)
2
GND
GND
( ) ARE FOR MAX810.
MAX803 AVAILABLE IN SC70-3 ONLY.
SC70-3/SOT23-3
*MAX803 ONLY
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
