World’s most popular IC

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Here’s a bit of nostalgia for you. My first, and to date only, attempt at programming used the world’s most popular integrated circuit ever manufactured—the venerable 555 Timer.

The 555 timer is a simple device. It is an 8-pin IC that can be configured as an oscillator, clock or simple timer with the addition of one or more components. Since its introduction in 1972 more than a billion of these devices are shipped each year. By my unofficial count that would add up to nearly 50 billion of the little black cockroaches timing their way through every manner of consumer and industrial products all over the world.

It was the late 1970s and Stan and I needed an easy way to make our front panel LED blink while our new preamplifier was warming up. The task of turning an LED on and off in a timed sequence might seem trivial by today’s standards but in those all-analog-days, it was rather a challenge. To turn an LED on and off you need an electronic switch. A simple transistor will do nicely but then you need another element to instruct the transistor to turn on and off and then that has to have some type of timing mechanism referenced to a clock and so on. (To put this in perspective the 555 Timer uses 25 transistors, 2 diodes and 15 resistors inside—as many parts as one channel of our entire preamp just to blink a light)

By placing a simple capacitor across two pins of the 555 we could adjust the on/off timing of a built-in switch by simply raising or lowering the value of the capacitor (bigger got you slower timing). It took me all of 5 minutes to breadboard the circuit and voila! A blinking green light erupted from the PCB and I went running across the building with excitement.

Today that story draws chuckles. The same size component can now hold bazillions of parts and perform what back in 1972 would have seemed like witchcraft.

We’ve come a long way, baby!