74LS90 Decade Counter IC (7490 IC) DIP-14 Package

The 74LS90 is a high-speed TTL Decade Counter integrated circuit designed for counting, frequency division, and timing applications in digital electronic systems. Commonly known as the 7490 IC, it is a 4-bit asynchronous (ripple) counter capable of counting from 0 to 9 (BCD) and automatically resetting to zero after the tenth count. The IC is widely used wherever reliable decimal counting and frequency division are required.

The 74LS90 consists of two internal counter sections: a divide-by-2 stage and a divide-by-5 stage. These sections can be connected together to form a divide-by-10 (decade) counter or configured independently to create various counting sequences such as BCD (Binary Coded Decimal), Modulo-2, Modulo-5, Modulo-6, Modulo-10, Modulo-12, and other custom counting circuits. This flexibility makes the IC suitable for a wide range of digital counting applications.

Built using Low-Power Schottky TTL (LS TTL) technology, the 74LS90 provides fast switching performance, low power consumption, and compatibility with standard TTL logic families. It operates from a standard 5V power supply and is available in a 14-pin DIP package, making it easy to use in breadboards, PCBs, and educational development projects.

The 74LS90 is commonly used in digital clocks, event counters, frequency divider circuits, timer systems, digital instruments, embedded systems, industrial automation, and educational electronics where accurate counting and frequency division are required.

Features

• 4-bit asynchronous decade (BCD) counter.

• Counts from 0 to 9 (Modulo-10).

• Internal divide-by-2 and divide-by-5 counter sections.

• Configurable for Modulo-2, Modulo-5, Modulo-6, Modulo-10, Modulo-12, and custom counting sequences.

• High-speed Low-Power Schottky TTL (LS TTL) technology.

• Standard 5V operating voltage.

• Fast switching performance.

• Low power consumption.

• TTL compatible.

• Reset inputs for flexible counter configuration.

• Available in a 14-pin DIP package.

• Easy integration into digital logic circuits.

Applications

• Digital clocks

• Frequency divider circuits

• Event counters

• Timer circuits

• Pulse counting systems

• BCD counting applications

• Digital instrumentation

• Industrial automation

• Embedded systems

• Robotics projects

• Electronic measurement equipment

• Educational and laboratory projects