DSDS1705/DS1706
DS1705/DS1706
3.3 and 5.0 Volt MicroMonitor
FEATURES
PIN ASSIGNMENT
• Halts and restarts an out–of–control microprocessor
PBRST
1
2
3
4
8
7
6
5
WDS
RST
ST
• Holds microprocessor in check during power tran-
sients
V
CC
GND
IN
NMI
• Automatically restarts microprocessor after power
failure
8–PIN DIP
(300 MIL)
• Monitors pushbutton for external override
PBRST
1
2
3
4
8
7
6
5
WDS
• Accurate 5%, 10% or 20% resets for 3.3 systems and
5% or 10% resets for 5.0 volt systems
V
RST (*RST)
ST
CC
GND
IN
NMI
• Eliminates the need for discrete components
8–PIN SOIC
(150 MIL)
• 3.3 volt 20% tolerance for use with 3.0 volt systems
• Pin compatible with the MAXIM MAX705/MAX706 in
PBRST
VCC
GND
IN
1
2
3
4
8
7
6
5
WDS
8–pin DIP and 8–pin SOIC
RST (*RST)
ST
• 8–pin DIP, 8–pin SOIC and 8–pin µ–SOP packages
• Industrial temperature range –40°C to +85°C
NMI
8–PIN µ–SOP
(118 MIL)
See Mech. Drawings
Section
DS1705 and DS1706_/R/S/T (*DS1706L and DS1706P)
PIN DESCRIPTION
PBRST
–
–
–
–
–
–
–
–
Pushbutton Reset Input
Power Supply
Ground
V
CC
GND
IN
NMI
ST
RST
*RST
Input
Non–maskable Interrupt
Strobe Input
Active Low Reset Output
Active High Reset Output
(DS1706P and DS1706L only)
Watchdog Status Output
WDS
–
DESCRIPTION
TheDS1705/DS17063.3or5.0VoltMicroMonitormoni-
tors three vital conditions for a microprocessor: power
supply, software execution, and external override. A
precision temperature compensated reference and
condition a non–maskable interrupt is generated. As
the voltage at the device degrades an internal power fail
signal is generated which forces the reset to an active
state. When V returns to an in–tolerance condition,
CC
comparator circuit monitors the status of V
device and at an upstream point for maximum protec-
tion. When the sense input detects an out–of–tolerance
at the
the reset signal is kept in the active state for a minimum
of 130 ms to allow the power supply and processor to
stabilize.
CC
ECopyright 1995 by Dallas Semiconductor Corporation.
All Rights Reserved. For important information regarding
patents and other intellectual property rights, please refer to
Dallas Semiconductor data books.
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