Datasheet

MAX6841–MAX6845
Ultra-Low-Voltage µP Reset Circuits and
Voltage Detectors
4 _______________________________________________________________________________________
Pin Description
Typical Operating Characteristics (continued)
(V
CC
= 1.5V, T
A
= +25°C, unless otherwise noted.)
NORMALIZED V
CC
RESET THRESHOLD
vs. TEMPERATURE
MAX6841-45 toc04
TEMPERATURE (°C)
NORMALIZED V
CC
RESET THRESHOLD
6040200-20
0.990
0.995
1.000
1.005
1.010
1.015
0.985
-40 80
V
TH
= 0.833V
NORMALIZED RESET IN THRESHOLD
vs. TEMPERATURE
MAX6841-45 toc05
TEMPERATURE (°C)
NORMALIZED RESET IN THRESHOLD
6040200-20
0.990
0.995
1.000
1.005
1.010
1.015
0.985
-40 80
POWER-UP/POWER-DOWN
CHARACTERISTICS (MAX6843AUKD3)
MAX6841-45 toc06
200ms/div
V
CC
1V/div
RESET
1V/div
PIN
MAX6841
MAX6842
MAX6843
MAX6845
MAX6844
NAME
FUNCTION
1——
Push-Pull (MAX6841) or Open-Drain (MAX6842) Active-Low Reset Output. RESET
changes from high to low when V
CC
drops below the selected reset threshold or
MR is pulled low. RESET remains low for the reset timeout period after V
CC
exceeds the device reset threshold and MR is released high.
—1—
RESET
Push-Pull (MAX6843) or Open-Drain (MAX6845) Active-Low Reset Output. RESET
changes from high to low when RESET IN drops below the 187.4mV reset
threshold (referenced to V
CC
) or MR is pulled low. RESET remains low for the
reset timeout period after RESET IN exceeds the reset threshold and MR is
released high.
222GND Ground
3——
Push-Pull Active-High Reset Output. RESET changes from low to high when V
CC
input drops below the selected reset threshold or MR is pulled low. RESET
remains high for the reset timeout period after V
CC
exceeds the device reset
threshold and MR is released high.
—— 1
RESET
Push-Pull Active-High Reset Output. RESET changes from low to high when the
RESET IN input drops below the 187.4mV reset threshold (referenced to V
CC
).
RESET remains high for the reset timeout period after RESET IN exceeds the reset
threshold.
—3 3
RESET IN
Adjustable Reset Input. High-impedance input for reset comparator. Connect this
pin to an external resistive-divider network to set the reset threshold voltage; the
typical threshold is 187.4mV (referenced to V
CC
). The MAX6843/MAX6844/
MAX6845 assert a reset signal when the V
CC
to RESET IN differential falls below
its threshold voltage.
444MR
Active-Low Manual Reset Input. Internal 20kΩ pullup to V
CC
. Pull low to force a
reset. Reset remains active as long as MR is low and for the reset timeout period
after MR goes high. Leave unconnected or connect to V
CC
if unused.
555V
CC
Supply Voltage. Monitored supply for the MAX6841/MAX6842.