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

The 74LS90, also known as the 7490 IC, is a high-speed 4-bit decade counter integrated circuit designed for counting, frequency division, and timing applications in digital electronic systems. It belongs to the Low-Power Schottky TTL (LS TTL) logic family and is widely used in digital clocks, timers, event counters, and frequency divider circuits.

The 74LS90 consists of two independent internal counter sections: a divide-by-2 stage and a divide-by-5 stage. These sections can be connected together to create a divide-by-10 (decade) counter, allowing the IC to count from 0 to 9 in Binary Coded Decimal (BCD) format. By configuring the reset and clock inputs appropriately, the IC can also be used to implement bi-quinary, modulo-12, modulo-16, and other custom counting sequences, making it highly versatile for a wide range of digital applications.

Operating from a 4.75V to 5.25V power supply, the 74LS90 delivers reliable high-speed performance with low power consumption. It provides an output current of 8 mA (HIGH level) and –400 µA (LOW level), ensuring compatibility with standard TTL logic circuits. The IC is designed to operate over a commercial temperature range of 0°C to 70°C, making it suitable for educational, industrial, and general-purpose electronic projects.

The 74LS90 is commonly used in digital counting systems, frequency division circuits, pulse counters, digital clocks, timers, instrumentation, embedded systems, and automation projects where accurate pulse counting and timing functions are required.

Features

• 4-bit decade (BCD) counter

• Divide-by-2 and divide-by-5 internal counter sections

• Configurable as divide-by-10, modulo-12, modulo-16, and custom counters

• Low-Power Schottky TTL (LS TTL) technology

• Operating voltage: 4.75V to 5.25V

• Output current: 8 mA (HIGH), –400 µA (LOW)

• High-speed counting performance

• Low power consumption

• Operating temperature range: 0°C to 70°C

• TTL-compatible inputs and outputs

• Standard DIP-14 package

• Reliable and stable operation

Applications

• Digital clocks

• Frequency divider circuits

• Event counters

• Pulse counting systems

• Timer circuits

• BCD counting applications

• Digital instrumentation

• Embedded systems

• Industrial automation

• Robotics projects

• Educational electronics experiments

• General-purpose digital logic circuits