DS1705/DS1706
3.3 and 5.0 Volt MicroMonitor
www.dalsemi.com
FEATURES
PIN ASSIGNMENT
Halts and restarts an out-of-control
microprocessor
Holds microprocessor in check during power
transients
Automatically restarts microprocessor after
power failure
Monitors pushbutton for external override
Accurate 5%, 10% or 20% resets for 3.3V
systems and 5% or 10% resets for 5.0V
systems
Eliminates the need for discrete components
3.3V 20% tolerance for use with 3.0V
systems
Pin-compatible with the MAXIM
MAX705/MAX706 in 8-pin DIP, 8-pin SOIC,
and µ-SOP
8-pin DIP, 8-pin SOIC and 8-pin µ-SOP
packages
Industrial temperature range -40°C to +85°C
PBRST
1
8
WDS
VCC
2
7
RST
GND
3
6
ST
IN
4
5
NMI
8-Pin DIP (300 -mil)
PBRST
1
8
WDS
VCC
2
7
RST(*RST)
GND
3
6
ST
IN
4
5
NMI
8-Pin SOIC (150-mil)
RST(*RST)
WDS
PBRST
VCC
1
2
3
4
8
7
6
5
ST
NMI
IN
GND
8-Pin µ-SOP (118-mil)
See Mech. Drawings Section
DS1705 and DS1706_R/S/T
(*DS1706L and DS1706P)
PIN DESCRIPTION
PBRST
VCC
GND
IN
NMI
ST
RST
*RST
WDS
- Pushbutton Reset Input
- Power Supply
- Ground
- Input
- Non-maskable Interrupt
- Strobe Input
- Active Low Reset Output
- Active High Reset Output
(DS1706P and DS1706L only)
- Watchdog Status Output
DESCRIPTION
The DS1705/DS1706 3.3- or 5.0-Volt MicroMonitor monitors three vital conditions for a microprocessor:
power supply, software execution, and external override. A precision temperature compensated reference
and comparator circuit monitor the status of VCC at the device and at an upstream point for maximum
protection. When the sense input detects an out-of-tolerance condition a non-maskable interrupt is
generated. As the voltage at the device degrades, an internal power fail signal is generated which forces
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