TL7700A Series
SUPPLY VOLTAGE SUPERVISORS
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POWER-ON RESET GENERATOR
AUTOMATIC RESET GENERATION AFTER
VOLTAGEDROP
WIDE SUPPLY VOLTAGE RANGE ... 3V TO
18V
PRECISION VOLTAGESENSOR
TEMPERATURE-COMPENSATED VOLTAGE
REFERENCE
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TRUE AND COMPLEMENT RESET OUTPUTS
EXTERNALLY ADJUSTABLE PULSE WIDTH
N
Minidip
DESCRIPTION
TheTL7700Aseriesaremonolithicintegratedcircuit
supplyvoltagesupervisorsspecificallydesi-gnedfor
use as reset controllers in microcomputer and mi-
croprocessorsystems. During power-upthe device
tests the supply voltageand keeps the RESET and
RESET outputs active (high and low, respectively)
as long as the supply voltage has not reached its
nominal voltage value. Taking RESIN low has the
sameeffect.Toensurethatthe microcomputersys-
temhasreset,theTL7700Atheninitiatesaninternal
timedelaythatdelaysthereturnofthe resetoutputs
totheirinactivestates.Sincethetimedelay formost
microcomputersandmicroprocessorsis intheorder
of several machine cycles, the device internal time
delayis determinedby an externaltime delay is de-
termined by an externalcapacitorconnectedto the
CT input (pin 3).
D
SO8
ORDERING NUMBERS
Temperature Range
0 to 70oC
Minidip
TL77XXACP
TL77XXAIP
S08
TL77XXACD
TL77XXAID
-25 to 85oC
PIN CONNECTION (top view)
td =1.3 x 104 x CT
Where : CT is in farads(F) and td inseconds (s). In
addition, when the supply voltage drops below the
nominal value, the outputs will be active until the
supplyvoltagereturns to the nominal value. An ex-
ternalcapacitor(typically0.1µF)mustbeconnected
to the REF output (pin 1) to reduce the influenceof
fast transientsin the supply voltage.
The TL7700AIseries is characterized for operation
from– 25oC to85oC ; theTL7700ACseriesis char-
acterizedfrom 0oC to70oC.
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April 2000