MAX6866UK43D6L-T Maxim Integrated, MAX6866UK43D6L-T Datasheet - Page 13

• Manufacturer Part Number: MAX6866UK43D6L-T
• Description: Supervisory Circuits
• Manufacturer: Maxim Integrated
• Series: MAX6854, MAX6855, MAX6856, MAX6858, MAX6860, MAX6861, MAX6862, MAX6863, MAX6864, MAX6865, MAX6866, MAX6867, MAX6868, MAX6869r

Specifications of MAX6866UK43D6L-T

• Number Of Voltages Monitored: 1
• Monitored Voltage: 1.2 V to 5.5 V
• Undervoltage Threshold: 4.193 V
• Overvoltage Threshold: 4.408 V
• Output Type: Active Low, Open Drain
• Manual Reset: Resettable
• Watchdog: Watchdog
• Battery Backup Switching: No Backup
• Power-up Reset Delay (typ): 900 ms
• Supply Voltage - Max: 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-23
• Chip Enable Signals: No
• Maximum Power Dissipation: 571 mW
• Minimum Operating Temperature: - 40 C
• Power Fail Detection: No
• Supply Current (typ): 7 uA
• Supply Voltage - Min: 1.1 V

input at different points in the program, rather than
pulsing the watchdog input high-low-high or low-high-
low. This technique avoids a stuck loop, in which the
watchdog timer would continue to be reset inside the
loop, keeping the watchdog from timing out.
Figure 6 shows an example of a flow diagram where
the I/O driving the watchdog input is set high at the
beginning of the program, set low at the beginning of
every subroutine or loop, then set high again when the
program returns to the beginning. If the program
should hang in any subroutine, the problem would
quickly be corrected, since the I/O is continually set low
and the watchdog timer is allowed to time out, causing
a reset or interrupt to be issued.
Figure 6. Watchdog Flow Diagram
Nanopower µP Supervisory Circuits with
______________________________________________________________________________________
SUBROUTINE OR
PROGRAM LOOP
SET WDI LOW
PROGRAM
SET WDI
RETURN
START
CODE
HIGH
Manual Reset and Watchdog Timer
Table 2. Threshold Suffix Guide
Table 3. Watchdog Timeout
SUFFIX
SUFFIX
225
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
S
L
4.509
4.388
4.266
4.193
4.095
3.998
3.900
3.802
3.705
3.608
3.510
3.413
3.315
3.218
3.120
2.998
2.925
2.852
2.730
2.633
2.559
2.438
2.340
2.255
2.180
2.133
2.048
1.950
1.853
1.755
1.623
1.536
MIN
MIN
1.5
95
V
CC
WATCHDOG TIMEOUT PERIOD
THRESHOLD FALLING
4.625
4.500
4.375
4.300
4.200
4.100
4.000
3.900
3.800
3.700
3.600
3.500
3.400
3.300
3.200
3.075
3.000
2.925
2.800
2.700
2.625
2.500
2.400
2.313
2.235
2.188
2.100
2.000
1.900
1.800
1.665
1.575
TYP
TYP
209
3.3
4.741
4.613
4.484
4.408
4.305
4.203
4.100
3.998
3.895
3.793
3.690
3.588
3.485
3.383
3.280
3.152
3.075
2.998
2.870
2.768
2.691
2.563
2.460
2.371
2.290
2.243
2.153
2.050
1.948
1.845
1.707
1.614
MAX
MAX
7.75
487
UNITS
UNITS
V
s
13