Texas Instruments SN74LS390N Dual Decade Counter DIP-16

The SN74LS390N from Texas Instruments is a versatile dual 4-bit decade counter in a compact DIP-16 package. It integrates eight flip-flops and additional gating to create two independent four-bit counters, each with its own clear and clock input. This dual divide-by-two and divide-by-five design allows flexible cycle lengths from 2 to 100, making it suitable for a wide range of counting and timing applications.

When configured as a bi-quinary counter, the separate divide-by-two circuit delivers a symmetrical square wave at the final output stage. Each counter stage provides parallel outputs, giving access to any submultiple of the input frequency for system-timing signals. The device also supports N-bit binary counting, enabling division by up to 256 per package.

Key Features

• Direct clear on each 4-bit counter
• Buffered outputs to reduce collector commutation
• Logic family: 74LS, base number 74390
• Clock frequency: 35MHz
• Supply voltage range: 4.75V to 5.25V
• Operating temperature: 0°C to 70°C
• 16-pin DIP package for easy breadboarding and prototyping

This IC is ideal for digital systems requiring reliable decade counting, frequency division, and timing generation. Its proven 74LS technology ensures low power consumption and compatibility with other TTL logic families.