Jellybean components
What are jellybean components? They are generic components that find
use in many applications. I give here a small list of these "jellybean"
components that always have lying around. Usually these are IC's or
transistors.
Transistors
I prefer US style transistor these days instead of the standard
european BCXXX series. The US componets are better characterised, and
sometimes have better properties at the same price:
2N3904 and 2N3906's are usually used for amplifier use.
2N2222 is usually for switching or high frequency work, but I also use
the BF199 for higher frequency work.
The JFET of choice I use the 2SK170/2SK117 N channel, and the J177 for
P channel work. They are used as high impedance amplifiers, while the
J177 is also very useful as a chopper or analog switch.
Small signal MOSFETs are the BS170 and BSS138 for N channels and the
BS250 P channel. These are sufficient for most switching jobs. The
lower threshold VN2222 is also a good transistor, but has less current
handling.
IC analog
TLC271 for its price and it has a offset compensation capability to
circumvent its relativly high input offset voltage.
MCP6001 cheap rail to rail input output CMOS opamp.
IC digital
I prefer true CMOS logic instead of TTL and HCT logic. The reason? Well
properly defined symmetric voltage levels.
74HC14 for interfacing analog projects with digital.
74HC00 for generic logic.
74LVC244, good voltage level translator. 5V tolerant.
Warrants its own chapter, it is a surprisingly versatile component. It
is more or less a logic IC that houses 4 inverters, but unlike most
chips that offer that function, the MOSFET's that make up each inverter
are brought out the IC package. This means that you can connect
directly to the drains and sources of the MOSFET's making the
inverters. So what? Big deal, you may think. But this makes this chip
quite versatile. This chip houses 4 inverters but can also be
configured into one of the following logic gates like NAND, NOR, a
transmission gate (analog switch) and offcourse 4 inverters.
Another of its strengths is its use in the analog domain. The MOSFET's
are all on the same die and have more or less the same characteristics
with very little deviation from device to device. This makes it very
usable as a versatile analog chip. I have only recently discovered this
IC and its many many uses as a analog device. Many example circuits can
be found as it is a staple chip used in many university courses. A lot
of the interesting circuits can be found in its discontinued analog
sibling the CA3600. It is built up exactly the same with the same
pinout but is characterised for analog operation. See the CA3600
datasheet for a few examples. I assume most of them will work with the
CD4007.
It is cheap, has many uses and available. There are alternatives like
the MOSFET arrays from Advanced Linear Devices Inc that have much
better characteristics and are more sensibly pinned out. But they cost
4 times as much and are hard to get. For most analog circuits this is
enough.
You can easely construct current mirror's with two mirrored sinks or
sources, differential amplifiers pairs, and much more. Basically the
rule is that 3 transistors are generally usable out of the package,
this is a consequence of the gates strapped together. Wish they made
one with just the MOSFET's brought out, and also in a more recent
technology then metal gate MOSFET's. TI's AUP technology would make for
some seriously speedy and low power logic.
Microcontrollers
Jellybean microcontrollers? Well they are not exactly generic but I use
a few types for almost all projects. They are mostly the ATtiny2313 and
the Atmega88. The 2313 has lots of digital interfacing options like
SPI/I2C and a hardware uart, a few timers and interrupts. Perfect for
many small microcontroller jobs.
For the more heavy work the mega88 is more suitable, with more I/O's
that are extended with the cheap 74HC595 shift registers. Most of my
projects utilise one of these controllers.
Back
Last update at: 11-06-2009