3-Pin Microprocessor Reset Circuits
below 1V, so does the IC’s ability to sink current at
RESET.
Also, with any pullup,
RESET
will be pulled high
as V
CC
decays toward 0. The voltage where this occurs
depends on the pullup resistor value and the voltage to
which it is connected.
Chip Information
TRANSISTOR COUNT: 275 (SOT23)
380 (SC70)
MAX803L/M/R/S/T/Z, MAX809J/L/M/R/S/T/Z, MAX810L/M/R/S/T/Z
Package Information
For the latest package outline information and land patterns,
go to
www.maxim-ic.com/packages.
Note that a “+”, “#”, or
“-” in the package code indicates RoHS status only. Package
drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
PACKAGE TYPE
3 SC70
3 SOT23
PACKAGE CODE
X3-2
U3-1
DOCUMENT NO.
Benefits of Highly Accurate
Reset Threshold
Most µP supervisor ICs have reset threshold voltages
between 5% and 10% below the value of nominal sup-
ply voltages. This ensures a reset will
not
occur within
5% of the nominal supply, but
will
occur when the sup-
ply is 10% below nominal.
When using ICs rated at only the nominal supply ±5%,
this leaves a zone of uncertainty where the supply is
between 5% and 10% low, and where the reset may or
may not be asserted.
The MAX8_ _L/T/Z use highly accurate circuitry to
ensure that reset is asserted close to the 5% limit, and
long before the supply has declined to 10% below
nominal.
_______________________________________________________________________________________
7