BCD 74HC390

[geeko]

Does anybody know how the BCD 74HC390 (Dual Decade Counter) works? I need help with this. If you know about any websites that can provide me with information about this component, please let me know. I need it fast.

Thanx. ;)

[ante]

geeko,

Welcome to this community. ;D

There is lots of info in the datasheet.

http://www.philipslogic.com/products/hc/pdf/74hc390.pdf

Ante ::)

[MP]

Hi geeko,
Here is a link to a frequency counter project using this chip. Hope it helps.

http://alternatezone.com/electronics/freq.htm

MP

[Kevin Weddle]

A modulus 10 counter uses flipflops and some associated logic to give you 10 stabile states. Each clock transistion will give you a change in output. There is a guy in the microcontroller section that is going to use a johnson counter to control the triggering of a one shot. With a latch on the last pin, he can trigger the one shot periodically to give to give him a pulse width modulated output. This is going to be summed with a clock to produce a special clock. Recall that a 555 will give you astable or one shot capability. The one shot has a variable duty cycle, but it will only produce it one time with a triggered input. You have to keep triggering the one shot if you want a continuous waveform.