bow...@gmail.com said: > For making a blinking LEDs, it is hard to beat a 74LS74. However, a PIC, is > probably less expensive! :)
Thanks. :) I was going to send a wise-ass comment, but then I checked some numbers. Digikey, one-off DIP pricing: $0.62 SN74LS74 $0.55 PIC10F200 $0.33 SN74HC74 So technically you are correct, but only because you are picked an ancient technology. Besides, the '74 needs a clock while the PIC has an internal clock calibrated to 1%. I suspect what's going on is that the '74 is pad limited(*) so you are paying per-pad rather than per gate. The PIC only has 8 pins, so if it's close to pad limited it will be cheaper. The PIC10F200 has 3 output pins so it can blink 3 LEDs independently while the '74 only has 2 FFs. High volume (whole tape, 2-3K) prices are $0.34, 0.22, and 0.10 ------ *) If you aren't familiar with pad-limited, it's a cool idea. Consider a chip that has N pins. Each pin needs a pad for the bond wire. Arrange those in a rectangle around the perimeter of your chip. That leaves a hole in the middle. Put your logic in there. If it doesn't fit, push the pads out until there is room. That makes your chip bigger and more expensive. If it fits with room leftover, you can add more logic for free. That's why low cost watches have so many features. -- These are my opinions. I hate spam. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
