Back to the Basics
As complicated as the world of engineering can be, understanding what transistors are can be surprisingly simple. It is simply a switch that lets current pass through it or not. Speaking digitally, this translates as being either a 1 or 0, on or off.
This constant fluctuation between on and off states if what powers today’s computers, including all your games, hardware, and anything else that interacts with a process. But this understanding is just the beginning of what makes up the hidden world of this technology. Let’s dive deeper.
FET - Field Effect Transistors
An FET is composed of three main components - the Gate, Drain and Source. When voltage is added to the gate it creates a pathway in the form of an electric field for electrons to flow (also known as current). MOSFETs or Metal Oxide Semiconductor FET are the most popular typeas they have high input impedance and a low output impedance. And since they’re voltage controlled they are much faster than their current-controlled BJT brothers, making them ideal for logic.
BJT - Bipolar Junction Transistor
A BJT is also composed of three main - the Base, Emitter, and Collector. When a small current is applied to the base a larger current is able to flow through it. There are two types of BJTs - NPN and PNP where N and P refer to N-type and P-type semiconductors. N-type semiconductors use electrons as the main carrier and P-type semiconductors use holes.
The Birth and Growth of Transistors
The transistor was invented by William Shockley, Walter Houser Brattain and John Bardeen who worked for Bell Labs way back in 1947. This invention is one of the most important in human history and is the birth of modern technology.
Technology moves quickly, and from the first transistor in 1947 we quickly progressed to the first integrated (IC) in 1958 and then to the first microprocessor in 1971. The first microprocessor was the Intel® 4004 which housed 2,300 transistors and was the size of a small fingernail. From here we’ve only improved. Chances are you’ve heard of Moore’s law but let’s just restate that real quick:
“The number of transistors incorporated in a chip will approximately double every 24 months.”
You can see from the infographic above that we’ve been shrinking the size of the transistor ever since its conception. But it seems that we’ve been coming to stand still as of late. We can still go smaller but we’re reaching a physical limit. You might have heard about the end of silicon, but that's a topic for another day.
How we’ve been able to improve and increase their number is by moving up, instead of out. Modern processors have moved away from 2D planar to 3D trigate transistors. Intel introduced these in their 22nm technology. With these new advances, processors are faster and at the same time consume much less power, which is great for mobile devices.
What the Future Brings
While it may seem that the progress of transistor miniaturization is slowing down, that doesn’t mean things are coming to an end. As the co-founder of Intel, Gordon Moore once said - “Whatever can be done, can be outdone.” This principle has never been more true for electronics design as we move into a connected future where everyday products are being designed with a new level of automation, intelligence and flexibility. At the core of this change is Altium Designer®, which features support for today’s most advanced high-speed design and rigid-flex technologies.
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About the AuthorMore Content by Alexsander Tamari