MAX803/MAX809/
MAX810
3-Pin Microprocessor Reset Circuits
General Description
Features
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 components
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 VCC supply voltage declines
below a preset threshold, keeping it asserted for at least
140ms after VCC has risen above the reset threshold.
Reset thresholds suitable for operation with a variety 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 pullup resistor that
can be connected to a voltage higher than VCC. 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
VCC, and the outputs are guaranteed to be in the correct
logic state for VCC 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.
●● Precision Monitoring of +2.5V, +3V, +3.3V, and
+5V Power-Supply Voltages
●● Fully Specified Over Temperature
●● Available in Three Output Configurations
• Open-Drain RESET Output (MAX803)
• Push-Pull RESET Output (MAX809)
• Push-Pull RESET Output (MAX810)
●● 140ms (min) Power-On-Reset Pulse Width
●● 12μA Supply Current
●● Guaranteed Reset Valid to VCC = +1V
●● Power Supply Transient Immunity
●● No External Components
●● 3-Pin SC70 and SOT23 Packages
Selector Guide and Ordering Information appear at end of data
sheet.
Typical Operating Circuit
VCC
MAX803
MAX809
RESET
Applications
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Computers
Controllers
Intelligent Instruments
Critical μP and μC Power Monitoring
Portable/Battery-Powered Equipment
Automotive
19-0344; Rev 9; 6/15
VCC
VCC
GND
*MAX803 ONLY
RPULLUP*
µP
RESET
INPUT
GND
