I have looked in the data sheets, as well as the TI article, but I am still unsure of the answer to this question:
What is the practical difference between a 7446 ("BCD to 7 segment decoder/driver with 30V open collector outputs"), a 7447 ("BCD to 7-segment decoder/driver with 15V open collector outputs"), a 7448 ("BCD to 7-segment decoder/driver with Internal Pullups"), and a 7449 ("BCD to 7-segment decoder/driver with open collector outputs").
To drive a normal 7 segment LED common-cathode display, can I use any of them? If not, what are they for?
Best Answer
'46 and '47 are for common-anode LEDs, whereas '48 and '49 are for common-cathode LEDs.
For the common-anode types, '46 allows a higher drive voltage than '47. For the common-cathode types, the difference between '48 and '49 is that '48 has "ripple-blanking input" (for suppressing leading zeroes), which the '49 has not.
There also are '246, '247 and '248 types that work like the above mentioned ones, but use a slightly different display pattern for "6" and "9" (namely with "tails").