hi,

am building a switching circuit that takes an input from 3 pins (3-bit), run through logic gates and provides a high pin on one of the 8 pins output. this is like a binary to decimal, except that only one of the 8 pins should be high.

am quite not sure if there is already a post earlier, however, i would need some help from anyone who can point me to the right direction, perhaps some sample circuits.

thanks a lot!

 

Hi,

except that only one of the 8 pins should be high.

Are you sure there is not a BCD decimal converter for your needs?

If not, what about using NMOS (maybe logic level) on each output or just using NOT gate?

Regards

 

You can use a BCD to decimal (or 3-bit binary to 8) converter such as the CD4028.

 

Or maybe you're looking for a 3 to 8 decoder like this:

http://www.nxp.com/documents/data_sheet/74HC_HCT238.pdf

 

If you want a switching using 3 pins to choosing one from eight inputs then it should be CD4051, if you want a decoder then you can using CD4028.

 

Not quite sure why posters are recommending a CD4028, which is a BCD to Decimal decoder?
The OP says in his first post that he only requires 8 outputs, not 10 ?

A 3 to 8 decoder would seem to fit those specific requirements better....or have I missed something?..

 

Use an 8bit bi-directional multiplexer/demultiplexer like this

http://www.st.com/web/en/resource/technical/document/datasheet/CD00000317.pdf

The control pins AB and C determine which channel (0-7) is connected to the common in/out pin (pin#3).

Note that channel numbers do not coincide with PIN numbers.

 

Not quite sure why posters are recommending a CD4028, which is a BCD to Decimal decoder?
The OP says in his first post that he only requires 8 outputs, not 10 ?

A 3 to 8 decoder would seem to fit those specific requirements better....or have I missed something?..

If you go to buy something, the thing cost US$10, and then does it matter what you have are US$10 or $20, but you can't only have $9, is that right?

 

Not quite sure why posters are recommending a CD4028, which is a BCD to Decimal decoder?
The OP says in his first post that he only requires 8 outputs, not 10 ?

A 3 to 8 decoder would seem to fit those specific requirements better....or have I missed something?..

You can use 3-bits of the 4-bit BCD input to get a 3-bit to 8 output decoder. You just ignore the other input bit and the two extra outputs. So whether a 3 to 8 decoder is better depends upon your definition of "better".

 

(..) or have I missed something?..

The OP has missed to explain the boolean function (or truth table) he needs.