7490

7490 is a numeric designation used for multiple product types, but in electronics it most commonly refers to a 4-bit binary counter integrated circuit in the 7400-series TTL family. Variants exist in TTL and CMOS technologies, with different supply voltages and pinouts depending on the manufacturer.

Operation and role: The device accepts clock pulses and increments its four outputs with each pulse, producing a binary count from 0 to 15 before wrapping back to zero. It typically includes inputs to asynchronously reset the count to zero, allowing the counter to be restarted on demand. The 7490 is widely used as a building block for frequency division and event counting; by cascading stages or combining counters, designers can realize modulo-n counters suitable for timers and digital displays.

Applications: It is used in digital clocks, counters for measurement and timing circuits, and various educational and hobbyist projects. Its straightforward behavior and availability across vendors made it a staple component in early digital electronics and still serves as a reference design in simple counting tasks.

Variants and compatibility: The 7490 family encompasses TTL versions and CMOS equivalents, with differences in voltage ranges, pinouts, and output characteristics across manufacturers. While modern counter functions are often implemented with more integrated solutions in newer technologies, 7490-compatible parts remain common for compatibility, retro hardware projects, and teaching.

In summary, the 7490 denotes a 4-bit binary counter component historically central to TTL counter designs, valued for its simplicity, ease of use, and role as a fundamental digital building block. Related topics include other 7400-series counters and general counter circuitry.