MB3773 Datasheet, PDF (24/31 Pages) Fujitsu Component Limited. – Power Supply Monitor with Watch-Dog Timer

MB3773
Description of Application Circuits
Using one MB3773, this application circuit monitors multiple microprocessor in one system. Signals from each microprocessor are
sent to FF1, FF2 and FF3 clock inputs. Figure 2 shows these timings. Each flip-flop operates using signals sent from microprocessor
as its clock pulse. When even one signal stops, the relevant receiving flip-flop stops operating. As a result, cyclical pulses are not
generated at output Q₃. Since the clock pulse stops arriving at the CK terminal of the MB3773, the MB3773 generates a reset signal.
Note that output Q₃ frequency f will be in the following range, where the clock frequencies of CK₁, CK₂ and CK₃ are f₁, f₂ and f₃
respectively.
f-1-0^{--  1-f-  -f1--}1^{- + -f1--}2^{- + -f1-}3^--
where f0 is the lowest frequency among f₁, f₂ and f₃.
Document Number: 002-08513 Rev. *A
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