Supply Voltage Supervisor w/Watchdog Input and Manual Reset
UM706xS SOP8
UM708xS SOP8
General Description
The UM706xS/UM708xS series are cost effective system power supply supervisory circuits
designed to monitor the power supplies in digital systems.
The UM706xS provides power-supply monitoring circuitry that generates a reset output during
power-up, power-down, and brownout conditions. The reset output remains operational with VCC
as low as 1V. Independent watchdog monitoring circuitry is also provided. This is activated if the
watchdog input has not been toggled within 1.6 seconds. In addition, there is a 1.25V threshold
detector for power-fail warning, low battery detection, or to monitor an additional power supply.
An active low debounced manual reset input is also included.
The UM708xS is the same as the UM706xS, except an active-high reset is substituted for the
watchdog timer. All parts are available in a small outline SOP8 package.
Applications
Features
Applications using DSPs, Microcontrollers Wide Operation Voltage Range of 1V to 5.5V
or Microprocessors
Programmable Controls
Computers
Correct Logic Output Guaranteed to
VCC=1.0V
Precision Supply-Voltage Monitor: 2.63V,
2.93V, 3.08V,4.38V,4.63V
Embedded System
200ms Reset Pulse Width
Independent Watchdog Timer-1.6s Timeout
(UM706xS)
Active-high Reset Output (UM708xS)
Voltage Monitor for Power-Fail or
Low-Battery Warning
Industrial Equipments
Intelligent Instrument
Wireless Communications Systems
Temperature Range: -40°C to +85°C
Supply Current of 80μA (Typ.)
Pin Configurations
Top View
8
7
6
5
1
2
3
4
8
7
6
5
MR
VCC
WDO(RESET)*
UM706(708)*
RESET
XS
XX
GND
PFI
WDI(NC)*
PFO
1
2
3
4
XX: Week Code
( )* for UM708xS
UM706xS
( )* for UM708xS
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http://www.union-ic.com Rev.02 May.2014 1/15