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INTRODUCTION
This E-Book is a
handy reference for many common chips. Each page
contains a pinout, notes and circuits using the chip.
It also has Chip Resistor
identification Surface Mount Transistor
Surface Mount Diode/Zener and
Surface Mount Outlines
If you are designing a project, it is a good idea to consider the economics
of how it should be designed.
There are basically two approaches:
1. Using discreet chips
2. Using a microcontroller.
The first thing to consider is the "commercial value" of the
project.
If it has "high commercial value," you should be aiming at
keeping the circuit-operation a secret.
Why allow your design to be copied?
We have already talked about the speed of copying on TE Interactive
website. A
product can be dismantled, copied and prototyped in less than a week by
industrious little beavers! I
have seen this in action with boards for arcade games. Within a
week, a board containing more than 40 chip was copied and released onto
the market. These boards had a microprocessor and a bank of memory chips.
It was old technology by today's standards and was quite easy to
duplicate. Modern microcontrollers have a "security" feature that makes
duplication very difficult.
Why let month's of work go down the drain?
One of the ways to protect your idea is to design it around a microcontroller.
In fact, one of the original uses for a microcontroller (PIC
microcontroller) was to scramble
information on a data bus so the program could not be copied. These
devices were called "dongles" and proved to be so effective that
governments refused to purchase programs requiring a dongle! Sales
declined to such a point that dongles have now been disbanded.
Some manufacturers include a microcontroller to merely complicate a
project and frustrate copying.
No matter how you look at them, micro's are certainly an effective addition
to any design.
Not only will your project look up-to-date but it can be simpler in
design, smaller in size and include features you never thought possible.
And you will feel a great sense of satisfaction by including
a micro.
I'm not advocating adding an unnecessary micro, but if you can reduce a 7
chip project to 2 or 3 chips, you will know what I mean.
Many of the chips in this E-Book are nearly 20 years old and very simple
in operation.
Very little thought went into their makeup and circuits requiring gating
chips are ripe for conversion to a micro. As an example, a old telephone dialing
project using 14 chips was converted to an 18-pin microcontroller - with
no other devices!
In the process, the capability increased 400% and the cost fell by 60%.
OP-AMPS
Op-amps are different.
If a circuit needs to detect very small voltages or waveforms, an op-amp
is a good choice. You can get 4 op-amps in a single package for about
$1.00, so they are not an expensive addition.
If only a single stage of amplification is needed,
a transistor may be the answer.
Whenever a signal is about 3v or greater, a micro can take care of the
processing. These are the things you have to take into account when designing
a
circuit. Our subscription section on the website has a Basic Electronics
Course and PIC Microcontroller Course to help you in this direction.
SECURITY
The main advantage of a micro is the security feature.
The program can be protected from prying eyes via a Code Protection
(CP)
feature. A micro also has the
ability to be updated with a new program and
this can save changing component values. Many micros are
re-programmable
and the latest versions are re-programmable while fitted to the PC board.
This is called "In-Circuit Programming."
Once you get into designing with a microprocessor, you will never look
back.
Everything you work-on will be considered as a micro-design.
The break-even point between a micro and individual chips can be as low as 3 or 4
chips.
It's not just the basic cost of production of a module but the
head-start you have and the on-going
protection you are afforded - there is much less chance of someone copying a microcontroller design.
CMOS CHIPS
Many of the chips we have covered in this data book are common CMOS chips.
Some have upgraded versions such as "HC" for "high-speed CMOS"
and "LP" for low power versions.
You will need to contact your supplier about the suitability of
using a particular chip. Also, make sure supplies will be available in the
future. Many of these chips are being phased out. They are
disappearing for two reasons.
The cost of producing a simple gate is about the same as a micro! And yet
the selling price is less than one-tenth!
In addition, the demand for simple gates is reducing with large
manufacturers opting for "masked ROM micro's" and single-chip
designs. They are simply dying a natural death.
Don't get left behind.
If you want to learn more about the skills of using chips, transistors, micro's and circuit design, go to
TALKING ELECTRONICS
Interactive website.
The subscription section contains a course on Basic Electronics and
PIC
Microcontroller Programming. The site also has many
projects in the FREE Projects Section, so everyone is catered for.
Colin
Mitchell
5-08-2004