This post explains for the TTL.

The Part Number is 7490, DM7490.

The function of this TTL is Decade and Binary Counter.

The pacakge is 14 Pin Type

Manufacturer: Fairchild Semiconductor

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## Description

**7490** is Decade and Binary Counter. This is a popular integrated circuit (IC) from the 74xx series of logic devices. It is a decade counter and binary counter IC that can be used in various digital counting and frequency division applications. The 7490 has four synchronous decade (BCD) counters in a single package, which means it can count in decimal (base-10) and binary (base-2) modes.

Block Diagram

1. Binary Counting: In binary counting, each count represents a unique binary number. For example, in a 3-bit binary counter, the counts will go from 000 (binary for 0) to 111 (binary for 7) before rolling over to 000 again. Binary counters are widely used in digital systems and microcontrollers for various purposes, including sequencing, addressing, and timing.

2. Decade (BCD) Counting: In decade counting, each count represents a unique decimal digit, ranging from 0 to 9. The primary use of BCD counters is for applications that require direct display or processing of decimal numbers. For example, in a 4-bit BCD counter, the counts will go from 0000 (BCD for 0) to 1001 (BCD for 9) before rolling over to 0000 again.

This TTL IC can be used in a variety of digital counting applications, such as frequency dividers, digital timers, and event counters.