This datasheet details the HD74HC490 dual 4-bit decade counter, covering features, function tables, pin arrangements, and DC/AC electrical characteristics.
The HD74HC490 is a dual 4-bit decade counter containing eight master-slave flip-flops. It allows for BCD count sequences of any length up to divide-by-100 using a single chip. The device features individual clock, clear, and set-to-9 inputs for each counter, along with buffered outputs to reduce susceptibility to collector communication. It supports high-speed operation with a typical propagation delay of 13 ns and operates over a wide voltage range of 2 to 6 V.
| Propagation delay (Clock to QA) | 13 ns typ |
|---|---|
| Operating Voltage | 2 to 6 V |
| Maximum Input Current | 1 mA |
| Quiescent Supply Current | 4 mA max |
| Operating Temperature Range | -40 to +85°C |
A single HD74HC490 can implement BCD count sequences up to divide-by-100.
Yes, each decade counter has individual clock, clear, and set-to-9 inputs.
The typical propagation delay from clock to QA is 13 ns when CL is 50 pF.