74LS90 Decade Counter
Binary counters are great components when working with logic level circuits. When working with a binary counter, you simply need a clock input in the form of a square wave that gives a signal into the CP1 pin. The pin Q0 should externally be connected to the CP1 pin to ensure that the counter will count upward in binary. This binary counter works with a falling edge on the clock signal to switch to the next number, which means that the output of the counter will change every time when the clock signal transitions from a logic high to a logic low.
This specific binary counter has three different types of counters that you can set up to be used as 3 three different types of counters, namely BCD decade counter, symmetrical bi-quinary divide by ten counter and divide by two and divide by five counter.
The LS family of logic gates can communicate with the HCT and VHC families, which are the more common families in modern circuits since they are able to communicate with almost all the other families of logic level gates. This makes it convenient, because you do not have to stick to a specific family, and you can mix the families as needed when some gates are not available at a store near you.
Technical specifications:
Supply voltage | 5.5V |
| Min input high voltage | 2V |
| Max input low voltage | 0.8V |
| Output high voltage | 3.5V |
| Supply current | 15mA |
| Max clock frequency CP0 | 32MHz |
| Max clock frequency CP1 | 16MHz |
Pin layout:
Truth table:
