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 lar-trimmed ret 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 asrted low when V CC falls below the ret threshold, or when the manual ret input (MR ) is asrted low. RESET remains asrt-ed for at least 100ms after V CC ris above the ret threshold and MR is deasrted.
The watchdog pul output (WDPO ) utilizes an open-drain configuration. It can be triggered either by a fast timeout fault (watchdog input puls are too clo to each other) or a slow timeout fault (no watchdog input pul is obrved within the timeout period). The watchdog timeout is measured from the last falling edge of watchdog input (WDI) with a minimum pul width of 300ns. WDPO is asrted for 1ms when a fault is obrved. Eight lar-trimmed timeout periods are available.
The MAX6323/MAX6324 are offered in a 6-pin SOT23package and operate over the extended temper
ature range (-40°C to +125°C).
Applications
Automotive Industrial Medical
Embedded Control Systems
Features
♦Min/Max (Windowed) Watchdog, 8 Factory-Trimmed Timing Options
♦Puld Open-Drain, Active-Low Watchdog Output ♦Power-On Ret
♦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 Ret Input ♦Guaranteed Ret Valid to V CC = +1.2V
MAX6323/MAX6324
µP Supervisory Circuits with Windowed (Min/Max) Watchdog and Manual Ret
________________________________________________________________Maxim Integrated Products
1
19-1838; Rev 4; 12/05
Pin Configuration
Ordering Information
Typical Operating Circuit appears at end of data sheet.
*See Figure 1 for operation.
For pricing, delivery, and ordering information,plea contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at
Watchdog Timeout
M A X 6323/M A X 6324
µP Supervisory Circuits with Windowed (Min/Max) Watchdog and Manual Ret 2_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V CC = full range, T A = -40°C to +125°C, unless otherwi noted. Typical values are at V CC = 3V, T A = +25°C.) (Note 1)
Stress beyond tho listed under “Absolute Maximum Ratings” may cau permanent damage to the device. The are stress ratings only, and functional operation of the device at the or any other conditions beyond tho indicated in the operational ctions of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Terminal Voltage (with respect to GND)
V CC ..................................................................-0.3V to +6.0V MR , RESET (MAX6323), -0.3V to (V CC + +0.3V)WDPO , RESET (MAX6324)..............................-0.3V to +6.0V Input Current, V CC , WDI, MR ..............................................20mA Output Current, RESET , WDPO ..
........................................20mA Rate of Ri, V CC ............................................................100V/µs
Continuous Power Dissipation (T A = +70°C)
6-Pin SOT23 (derate 8.7mW/°C above +70°C)..........696mW Operating Temperature Range .........................-40°C to +125°C +150°C Storage -65°C to +150°C Lead Temperature (soldering, 10s).................................+300°C
MAX6323/MAX6324
µP Supervisory Circuits with Windowed (Min/Max) Watchdog and Manual Ret
_______________________________________________________________________________________
3
ELECTRICAL CHARACTERISTICS (continued)
(V CC = full range, T A = -40°C to +125°C, unless otherwi noted. Typical values are at V CC = 3V, T A = +25°C.) (Note 1)
Note 1:Devices are tested at T A = +25°C and guaranteed by design for T A = T MIN to T MAX , as specified.Note 2:WDPO will pul low if a falling edge is detected on WDI before this timeout period expires.
Note 3:To avoid a potential fake fault, the first WDI pul after the rising edge of RESET or WDPO will not create a fast watchdog
timeout fault.
Note 4:WDPO will pul low if no falling edge is detected on WDI after this timeout period expires.
M A X 6323/M A X 6324
职业技能提升培训µP Supervisory Circuits with Windowed (Min/Max) Watchdog and Manual Ret 4_______________________________________________________________________________________
0303540252015105-40
20
-20
40
60
80
TEMPERATURE (°C)
SUPPLY CURRENT vs. TEMPERATURE
S U P P L Y C U R R E N T (µA )
030205-40
20
-20
40
60实验室英语
80
TEMPERATURE (°C)
P O W E R -D O W N R E S E T D E L A Y (µs )
POWER-DOWN RESET DELAY
vs. TEMPERATURE
2515100.9985
0.9990
0.9995
1.00001.0005-40
20
-20
40
60
动物的作文300字
80
M A X 6323/24-04
TEMPERATURE (°C)
R E S E T T H R E S H O L D
NORMALIZED RESET THRESHOLD
vs. TEMPERATURE
0.9980
淘宝和天猫的关系0.994
1.0041.0061.008-40
20
-20
40
60
80
M A X 6323/24-05
TEMPERATURE (°C)
P O W E R -U P R E S E T T I M E O U T
NORMALIZED POWER-UP RESET TIMEOUT
vs. TEMPERATURE
1.0021.0000.9980.996
0.992
1.0041.0021.0000.9981.0061.008
-40
20
-20
40
60
80
M A X 6323/24-06
TEMPERATURE (°C)
NORMALIZED WATCHDOG TIMEOUT PERIOD (FAST) vs. TEMPERATURE
N O R M A L I Z E D W A T C H D O G T I M E O U T P E R I O D (F A S T ) 0.9960.9940.995
1.0001.0010.9990.9970.9980.9961.0021.003-40
20
-
20
40
60
80
M A X 6323/24-07
TEMPERATURE (°C)
NORMALIZED WATCHDOG TIMEOUT PERIOD (SLOW) vs. TEMPERATURE
N O R M A L I Z E D W A T C H D O G T I M E O U T P E R I O D (S L O W )
0.992
1.0041.0021.0001.0061.008-40
20
-
20
钻石的英文40
60
80
M A X 6323/24-08
TEMPERATURE (°C)
N O R M A L I Z E D W A T C H D O G O U T P U T P U L S E W I D T H (µs )
NORMALIZED WATCHDOG OUTPUT PULSE WIDTH vs. TEMPERATURE
0.9980.996
0.994400
01
100
文化苦旅读书笔记
1000
MAXIMUM TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVE
10050150200250300350RESET COMPARATOR OVERDRIVE (mV)
M A X I M U M T R A N S I E N T D U R A T I O N (µs )
10
Typical Operating Characteristics
(V CC = full range, T A = +25°C, unless otherwi noted.)
401201008060140160
-40200-20406080
M A X 6323/24-03
TEMPERATURE (°C)
M R T O R E S E T D E L A Y (n s ) MR TO RESET DELAY vs. TEMPERATURE
200
MAX6323/MAX6324
µP Supervisory Circuits with Windowed (Min/Max) Watchdog and Manual Ret
_______________________________________________________________________________________5
500µs/div
MAX6323/24-10
WDI 2V/div 2V/div
WDPO FAST WATCHDOG TIMEOUT PERIOD
MAX6323AUT235ms/div
英语b级词汇
WDI 2V/div
2V/div
WDPO SLOW WATCHDOG TIMEOUT PERIOD
MAX6323AUT23Typical Operating Characteristics (continued)
(V CC = full range, T A = +25°C, unless otherwi noted.)
Pin Description
一盆眼泪M A X 6323/M A X 6324
µP Supervisory Circuits with Windowed (Min/Max) Watchdog and Manual Ret 6
_______________________________________________________________________________________
Detailed Description
The MAX6323/MAX6324 µP supervisory circuits main-tain system integrity by alerting the µP to fault condi-tions. In addition to a standard V CC monitor (for power-on ret, brownout detect, and power-down ret), the devices include a sophisticated watchdog timer that detects when the processor is running out-side an expected window of operation for a specific application. The watchdog signals a fault when the input puls arrive too early (faster than the lected t WD1timeout period) or too late (slower than the lect-ed t WD2timeout period) (Figure 1). Incorrect timing can lead to poor or dangerous system performance in tight-ly controlled operating environments. Incorrect timing could be the result of improper µP clocking or code execution errors. If a timing error occurs, the MAX6323/MAX6324 issue a watchdog pul output,independent from the ret output, indicating that sys-tem maintenance may be required.
Watchdog Function
A pul on the watchdog output WDPO can be trig-gered by a fast fault or a slow fault. If the watchdog input (WDI) has two falling edges too clo to each
other (faster than t WD1) (Figure 2) or falling edges that are too far apart (slower than t WD2) (Figur
e 3), WDPO is puld low. Normal watchdog operation is displayed in Figure 4 (WDPO is not asrted). The internal watch-dog timer is cleared when a WDI falling edge is detect-ed within the valid watchdog window or when the device’s RESET or WDPO outputs are deasrted. All WDI input puls are ignored while either RESET or WDPO is asrted. Figure 1 identifies the input timing regions where WDPO fault outputs will be obrved with respect to t WD1and t WD2. After RESET or WDPO deasrts, the first WDI falling edge is ignored for the fast fault condition (Figure 2).
Upon detecting a watchdog fault, the WDPO output will pul low for 1ms. WDPO is an open-drain output.Connect a pullup resistor on WDPO to any supply up to +6V.
V CC Ret
The MAX6323/MAX6324 also include a standard V CC ret monitor to ensure that the µP is started in a known state and to prevent code execution errors during power-up, power-down, or brownout conditions.RESET is asrted whenever the V CC supply voltage
Figure 1. Detailed Watchdog Input Timing Relationship
