©
1999 IMP, Inc. 408-432-9100/www.impweb.com 1
Key Features
Applications
◆ Computers and controllers
◆ CTI applications
◆ Embedded controllers
◆ Battery operated systems
◆ Intelligent instruments
◆ Wireless communication systems
◆ PDAs and handheld equipment
◆
Lower power, pin compatible replacements for
Maxim MAX706P/R/S/T, MAX708R/S/T
– 30% lower supply current:140µA vs. 200µA
◆
Precision power supply monitor
– 2.63V threshold (IMP706P/R, IMP708R)
– 2.93V threshold (IMP706S, IMP708S)
– 3.08V threshold (IMP706T, IMP708T)
– New 4.00V threshold (IMP706J, IMP708J)
◆
Debounced manual reset input
◆
Auxiliary voltage monitor comparator
– 1.25V threshold
– Battery monitor/auxiliary supply monitor
◆
Watchdog timer (IMP706P/R/S/T/J)
– Watchdog can be disabled by floating WDI
◆
200ms reset time delay
◆
Three reset signal options
– Active HIGH: IMP706P
– Active LOW: IMP706R/S/T/J
– Active HIGH & LOW outputs: IMP708R/S/T/J
◆
DIP, SO and MicroSO packages
◆
Guaranteed RESET assertion to V
CC
= 1.1V
Block Diagrams
IMP706P/R/S/T/J, IMP708R/S/T/J
IMP706P/R/S/T/J, IMP708R/S/T/J
POWER MANAGEMENT
3/3.3/4.0V
3/3.3/4.0V
µ
µ
P Super
P Super
visor Cir
visor Cir
cuits
cuits
– Lo
– Lo
w suppl
w suppl
y cur
y cur
r
r
ent
ent
– W
– W
atc
atc
hdog timer
hdog timer
– Br
– Br
o
o
wnout det
wnout det
ection
ection
The IMP706P/R/S/T/J and IMP708R/S/T/J CMOS supervisor circuits
monitor power-supply and battery voltage level, and
µP/µC operation.
A reset is generated when the supply drops below 2.63V (IMP706P/R,
IMP708R), 2.93V (IMP706S, IMP708S), 3.08V (IMP706T, IMP708T) or 4.00
(IMP706J, IMP708J).
The family offers several functional options. Each device generates a
reset signal during power-up, power-down and during brownout
conditions.
In addition, the IMP706P/R/S/T/J feature a 1.6 second watchdog timer.
The watchdog timer output will trigger a reset if connected to MR.
Unlike competitive devices, floating the WDI input pin disables the
watchdog timer.
The IMP708R/S/T/J have both active-HIGH and active-LOW reset out-
puts but no watchdog function. The IMP706P has the same pin-out and
functions as the IMP706R but has an active-HIGH reset output.
A versatile power-fail circuit, useful in checking battery levels and
non-5V supplies, has a 1.25V threshold. All devices have a manual
reset input.
All devices are available in 8-pin DIP, SO and the compact MicroSO
packages. The MicroSO package requires 50% less PC board area than
the conventional SO package.
RESET
RESET
V
CC
RESET
Generator
2.63V (IMP708R)
2.93V (IMP708S)
3.08V (IMP708T)
4.00V (IMP708J)
V
CC
+
–
+
MR
IMP708R/S/T/J
PFO
GND
1.25V
–
+
PFI
706P_02.eps
20kΩ
1.25V
–
+
MR
WDI
IMP706P/R/S/T/J
WDO
RESET
(RESET) IMP706P
PFO
GND
V
CC
20kΩ
RESET
Generator
2.63V (IMP706P/R)
2.93V (IMP706S)
3.08V (IMP706T)
4.00V (IMP706J)
V
CC
+
–
+
PFI
Timebase
Watchdog
Timer
Transition
Detector
706P_01.eps
