19-2656; Rev 1; 1/03
碌P Reset Circuits with Long Manual Reset
Setup Period
General Description
The MAX6443鈥揗AX6452 low-current microprocessor
reset circuits feature single or dual manual reset inputs
with an extended 6.72s setup period. Because of the
extended setup period, short switch closures (nuisance
resets) are ignored.
On all devices, the reset output asserts when any of the
monitored supply voltages drops below its specified
threshold. The reset output remains asserted for the
reset timeout period (210ms typ) after all monitored
supplies exceed their reset thresholds. The reset output
is one-shot pulse asserted for the reset timeout period
(140ms min) when selected manual reset input(s) are
held low for an extended setup timeout period of 6.72s.
These devices ignore manual reset transitions of less
than 6.72s (typ).
The MAX6443鈥揗AX6448 are single fixed-voltage 碌P
supervisors. The MAX6443/MAX6444 have a single
extended manual reset input. The MAX6445/MAX6446
have two extended manual reset inputs. The MAX6447/
MAX6448 have one extended and one immediate manual
reset input.
The MAX6449鈥揗AX6452 have one fixed-threshold 碌P
supervisor and one adjustable-threshold 碌P supervisor.
The MAX6449/MAX6450 have two delayed manual
reset inputs. The MAX6451/MAX6452 have one delayed
and one immediate manual reset input.
The MAX6443鈥揗AX6452 have an active-low
RESET
with push-pull or open-drain output logic options. These
devices, offered in small SOT packages, are fully guar-
anteed over the extended temperature range (-40擄C to
+85擄C).
Features
o
Single- or Dual-Supply Voltage Monitors
o
Precision Factory-Set Reset Thresholds from
1.6V to 4.6V
o
Adjustable Threshold to Monitor Voltages Down
to 0.63V (MAX6449鈥揗AX6452)
o
Single or Dual Manual Reset Inputs with Extended
6.72s Setup Period
o
Optional Short Setup Time Manual Reset Input
(MAX6447/MAX6448 and MAX6451/MAX6452)
o
Immune to Short Voltage Transients
o
Low 6碌A(chǔ) Supply Current
o
Guaranteed Valid Reset Down to V
CC
= 1.0V
o
Active-Low
RESET
(Push-Pull or Open-Drain)
Outputs
o
140ms (min) Reset Timeout Period
o
Small SOT143 and SOT23 Packages
MAX6443鈥揗AX6452
Ordering Information
PART
MAX6443
US_ _L -T
MAX6444
US_ _L -T
TEMP RANGE
-40擄C to +85擄C
-40擄C to +85擄C
PIN-PACKAGE
4 SOT143-4
4 SOT143-4
Applications
Set-Top Boxes
Consumer Electronics
DVD Players
Modems
MP3 Players
Industrial Equipment
Automotive
Medical Devices
Note:
The 鈥淿 _ 鈥?is a placeholder for the threshold voltage level
of the devices. A desired threshold level is set by the two-num-
ber suffix found in Table 1. All devices are available in tape-
and-reel only. There is a 2500-piece minimum order increment
for standard versions (Table 2). Sample stock is typically held
on standard versions only. Nonstandard versions require a
minimum order increment of 10,000 pieces. Contact factory for
availability.
Pin Configurations
TOP VIEW
GND
1
4
V
CC
MAX6443
MAX6444
RESET
2
3
MR1
SOT143
Pin Configurations continued at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim鈥檚 website at www.maxim-ic.com.