seven segment

[shefaliraina]

i want to use a common cathode 7 segment with decoder ic7447using ULN2003..hw to do that??

 

[vogels]

You would want to use the ULN2003 as an input for the decoder, which accepts BCD.( each digit of a number is coded in binary rather then the entire number which wouldnt matter for a single digit display) connect the outputs of the decoder to the corresponding inputs of the display. Hope this helps

 

[Mikebits]

There is absolutely no reason to use a ULN2003 to drive a 7447 decoder chip. The 2003 is a open collector, high current darlington arrays used for driving things like motors or relays. OP, you need to give more details on what you want to do.

 

[crutschow]

You can't. To drive a common-cathode display you need a high side driver, and the 7447 and 2003 are NPN open collector low side drivers.

To do this you could use a PNP driver for each display segment controlled by the 7447 outputs. Connect the transistor emitters to the plus supply and the bases through a resistor to their respective 7447 outputs. Connect the transistor collectors through a resistor to the respective display segment. Ground the display common-cathode terminal.