cd4026 help

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mikeb
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cd4026 help

Post by mikeb » Wed Feb 05, 2003 4:32 pm

is there any one with knowledge as to how wouldi interface 2 or more cd4026be counter ic's to create a multi digit display. the chip has a clock input pin which i have connected to a 1 hz source, a clock inhibit (active high pin which i have connected to ground. it also has a display enable in pin which i have connected to +5 volts, the pin is active high. the ic is properly grounded and pin 16 is also connected to the 5 volt supply. when i try to connect a second cd4026 i connect the carryout pin to the second ic clock pin, and connect the second ic clock inhibit pin to the 5 volt source and the dsiplay enable pin to the 5 volt source, pin 16 second ic is connected to the 5 volt source, and the ic is grounded. this seem to be the correct interface for the 2 ic's to count in a mulit digit display, the first ic will count 0 to 9, the carryout pin pulses the clock pin of the second ic as it should to display a 1 after the count has going thru 1 cycle but the second display does not indicate nothing but the 0 it starts with when the unit is first turned on. im thinking im missing a connection somewhere that makes the ic,s interface together. the ic's are cd4026be with decoded display outputs.

Chris Foley
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Joined: Mon Jan 13, 2003 1:01 am
Location: Chicago IL
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Re: cd4026 help

Post by Chris Foley » Wed Feb 05, 2003 9:17 pm

Hi, Lex. Your description of the problem may show the solution. You said you "connect the second ic clock inhibit pin to the 5 volt source". That will prevent the chip from counting. Try grounding that pin. The datasheet for that IC is available at..<p>http://focus.ti.com/docs/prod/productfo ... er=CD4026B<p>and a photostat pdf is available at...<p>http://www-s.ti.com/sc/ds/cd4026b.pdf<p>Good luck.

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