MAX6323-MAX6324 Datasheet, PDF (1/12 Pages) Maxim Integrated Products – uP Supervisory Circuits with Windowed (Min/Max) Watchdog and Manual Reset

19-1838; Rev 3; 3/04
µP Supervisory Circuits with Windowed
(Min/Max) Watchdog and Manual Reset
General Description
The MAX6323/MAX6324 microprocessor (µP) supervi-
sory circuits monitor power supplies and µP activity in
digital systems. A watchdog timer looks for activity out-
side an expected window of operation. Six laser-
trimmed reset thresholds are available with ±2.5%
accuracy from +2.32V to +4.63V. Valid RESET output is
guaranteed down to V_CC = +1.2V.
The RESET output is either push-pull (MAX6323) or
open-drain (MAX6324). RESET is asserted low when
V_CC falls below the reset threshold, or when the manual
reset input (MR) is asserted low. RESET remains assert-
ed for at least 100ms after V_CC rises above the reset
threshold and MR is deasserted.
The watchdog pulse output (WDPO) utilizes an open-
drain configuration. It can be triggered either by a fast
timeout fault (watchdog input pulses are too close to
each other) or a slow timeout fault (no watchdog input
pulse is observed within the timeout period). The
watchdog timeout is measured from the last falling
edge of watchdog input (WDI) with a minimum pulse
width of 300ns. WDPO is asserted for 1ms when a fault
is observed. Eight laser-trimmed timeout periods are
available.
The MAX6323/MAX6324 are offered in a 6-pin SOT23
package and operate over the extended temperature
range (-40°C to +125°C).
Applications
Automotive
Industrial
Medical
Embedded Control Systems
Features
♦ Min/Max (Windowed) Watchdog,
8 Factory-Trimmed Timing Options
♦ Pulsed Open-Drain, Active-Low Watchdog Output
♦ Power-On Reset
♦ Precision Monitoring of +2.5V, +3.0V, +3.3V,
and +5.0V Power Supplies
♦ Open-Drain or Push-Pull RESET Outputs
♦ Low-Power Operation (23µA typ)
♦ Debounced Manual Reset Input
♦ Guaranteed Reset Valid to V_CC = +1.2V
Ordering Information
PART*
TEMP
RANGE
PIN-
RESET
PACKAGE OUTPUT
MAX6323_UT__-T -40°C to +125°C 6 SOT23-6 Push-Pull
MAX6324_UT__-T -40°C to +125°C 6 SOT23-6 Open Drain
*These devices are factory trimmed to one of eight watchdog-
timeout windows and one of six reset voltage thresholds. Insert
the letter corresponding to the desired watchdog-timeout window
(A, B, C, D, E, F, G, or H) into the blank following the number
6323 or 6324 (see Watchdog Timeout table). Insert the two-digit
code (46, 44, 31, 29, 26, or 23) after the letters UT for the desired
nominal reset threshold (see Reset Threshold Range table at end
of data sheet).
Note: There are eight standard versions of each device available
(see Standard Versions table). Sample stock is generally held on
standard versions only. Standard versions have an order incre-
ment requirement of 2500 pieces. Nonstandard versions have an
order increment requirement of 10,000 pieces. Contact factory for
availability of nonstandard versions.
TOP VIEW
MR 1
Pin Configuration
6 RESET
GND 2
MAX6323
MAX6324
5 WDPO
WDI 3
4 V_CC
SOT23
Typical Operating Circuit appears at end of data sheet.
Watchdog Timeout
WATCHDOG TIMEOUT*
SUFFIX
FAST
MAX
UNITS
SLOW
MIN
UNITS
A
1.5
ms
10
B
15
ms
100
ms
C
15
ms
300
D
15
ms
10
s
E
15
ms
60
F
23
ms
47
ms
G
39
ms
82
H
719
ms
1.3
s
*See Figure 1 for operation.
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