74LS90 PDF Datasheet – Decade and Binary Counter

This post explains for the TTL.

The Part Number is 74LS90.

The function of this semiconductor is Decade and Binary Counter.

The package is DIP 14 Pin type

Manufacturer: National Semiconductor

Preview images :

74LS90 pdf pinout


The 74LS90 is a popular integrated circuit (IC) chip that belongs to the 74LS series of TTL (Transistor-Transistor Logic) logic devices. Specifically, the 74LS90 is a decade counter/divider with a 4-bit binary output. It’s designed to count in decimal (base-10) and is often used in digital electronics for counting and frequency division applications.

Each of these monolithic counters contains four masterslave flip-flops and additional gating to provide a divide-bytwo counter and a three-stage binary counter for which the count cycle length is divide-by-five for the ’LS90 and divideby-eight for the ’LS93 All of these counters have a gated zero reset and the LS90 also has gated set-to-nine inputs for use in BCD nine’s complement applications To use their maximum count length (decade or four bit binary) the B input is connected to the QA output The input count pulses are applied to input A and the outputs are as described in the appropriate truth table A symmetrical divide-by-ten count can be obtained from the ’LS90 counters by connecting the QD output to the A input and applying the input count to the B input which gives a divide-by-ten square wave at output QA Features Y Y Typical power dissipation 45 m […]


1. Typical power dissipation 45 mW
2. Count frequency 42 MHz

2 page
74LS90 datasheet

The 74LS90 is widely used in digital circuits for various applications requiring counting and frequency division. It’s often used in conjunction with other ICs to create more complex counting sequences or timers. The ripple carry output makes it suitable for cascading multiple counters to achieve extended counting ranges.

74LS90 PDF Datasheet

74LS90 pdf