CMOS 4047 Digital Clock Circuit

| |

This circuit provides a digital square wave that can be viewed directly or used to drive other circuits. It used the CMOS 4047 Low-Power Monostable/Astable Multivibrator. As used in Tom Duncan's Adventures with Digital Electronic's Book, to drive CMOS Decade of 4-bit binary counters.


RC = 10M x 100nF = (10x106) x (100x10-9) = 1 Hz OscOut (Double Frequency of Q)
_
Q (Inverse of Q)
Q (Square Wave, Frequency RC Hz, 1:1 Mark:Space Ratio)
These 3 outputs can be viewed using an LED and 330R Resitor in series.
 
 
 
 
 
 
 
+----------+
Cext |1 +--+ 14| VCC
Rext |2 13| OSC
RCext |3 12| RETRIG
/AST |4 4047 11| /Q
AST |5 10| Q
/TR |6 9| RST
GND |7 8| TR
+----------+


<