MAX6887 MAXIM [Maxim Integrated Products], MAX6887 Datasheet - Page 11

• Manufacturer Part Number: MAX6887
• Description: Hex/Quad, Power-Supply Supervisory Circuits
• Manufacturer: MAXIM [Maxim Integrated Products]

At power-up, WDO goes high after t
The initial watchdog timeout period (t
diately after WDO is high. The initial watchdog timeout
period allows the µP to perform its initialization process.
A normal watchdog timeout period (t
ever WDI transitions from high to low after the initial
watchdog timeout period occurs. WDI monitors the tog-
gling output of the µP, indicating normal processor
behavior. If WDI does not toggle during the normal
watchdog timeout period (t
processor has stopped operating or is stuck in an infinite
execution loop, WDO goes low. WDO stays low until the
next transition on WDI. An initial watchdog timeout peri-
od (t
If WDO is connected to MR, the WDO will assert for a
short duration (~5µs), long enough to assert the RESET
output. Asserting RESET clears the watchdog timer and
WDO goes high. The reset output will remain asserted
for its timeout period after a watchdog fault. The watch-
dog timer stays cleared as long as RESET is low.
For better noise immunity, bypass each of the voltage-
detector inputs to GND with 0.1µF capacitors installed
as close to the device as possible. Bypass V
to GND with 1µF capacitors installed as close to the
device as possible. V
and BP are internally generated voltages and should
not be used to supply power to external circuitry.
WDI
Hex/Quad, Power-Supply Supervisory Circuits
) starts when WDO goes high.
Applications Information
______________________________________________________________________________________
CC
(when not externally supplied)
Layout and Bypassing
WD
), indicating that the
D-PO
WDI
WD
) applies when-
) applies imme-
(see Figure 3).
CC
and BP
*See thresholds options tables (Tables 1 and 2) for actual under-
voltage and overvoltage thresholds.
PROCESS: BiCMOS
MAX6888AETE
MAX6888BETE
MAX6888CETE
MAX6888DETE
MAX6888EETE
MAX6888FETE
MAX6888GETE
MAX6888HETE
MAX6888QETE
MAX6888IETE
MAX6888JETE
MAX6888KETE
MAX6888LETE
MAX6888METE
MAX6888NETE
MAX6888OETE
MAX6888PETE
MAX6888RETE
PART
Selector Guide (continued)
5.0
5.0
5.0
5.0
5.0
5.0
IN1
Adj
Adj
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
NOMINAL INPUT
VOLTAGE (V)*
IN2
Adj
Adj
3.3
3.3
3.3
2.5
2.5
2.5
2.5
1.8
3.3
3.3
3.3
2.5
2.5
2.5
2.5
1.8
Chip Information
IN3
Adj
Adj
Adj
Adj
Adj
Adj
2.5
2.5
1.8
1.8
1.8
1.5
2.5
2.5
1.8
1.8
1.8
1.5
IN4
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
1.8
1.5
1.8
1.5
TOLERANCE
(%)
10
10
10
10
10
10
10
10
10
5
5
5
5
5
5
5
5
5
11