Protoboard

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  • Publicado : 11 de mayo de 2010
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General characteristics
* Supply: 3 to 15V, small fluctuations are tolerated.
* Inputs have very high impedance (resistance), this is good because it means they will not affect the part of the circuit where they are connected. However, it also means that unconnected inputs can easily pick up electrical noise and rapidly change between high and low states in an unpredictable way. This islikely to make the IC behave erratically and it will significantly increase the supply current. To prevent problems all unused inputs MUST be connected to the supply (either +Vs or 0V), this applies even if that part of the IC is not being used in the circuit!
* Outputs can sink and source only about 1mA if you wish to maintain the correct output voltage to drive CMOS inputs. If there is noneed to drive any inputs the maximum current is about 5mA with a 6V supply, or 10mA with a 9V supply (just enough to light an LED). To switch larger currents you can connect a transistor.
* Fan-out: one output can drive up to 50 inputs.
* Gate propagation time: typically 30ns for a signal to travel through a gate with a 9V supply, it takes a longer time at lower supply voltages.
*Frequency: up to 1MHz, above that the 74 series is a better choice.
* Power consumption (of the IC itself) is very low, a few µW. It is much greater at high frequencies, a few mW at 1MHz for example.
There are many ICs in the 4000 series and this page only covers a selection, concentrating on the most useful gates, counters, decoders and display drivers. For each IC there is a diagram showingthe pin arrangement and brief notes explain the function of the pins where necessary. The notes also explain if the IC's properties differ substantially from the standard characteristics listed above.
If you are using another reference please be aware that there is some variation in the terms used to describe input pins. I have tried to be logically consistent so the term I have used describesthe pin's function when high (true). For example 'disable clock' on the 4026 is often labelled 'clock enable' but this can be confusing because it enables the clock when low (false). An input described as 'active low' is like this, it performs its function when low. If you see a line drawn above a label it means it is active low, for example:   (say 'reset-bar').
Datasheets are available from:* DatasheetArchive.com
* Datasheets.org.uk
* DatasheetCatalog.com

Static precautions
The CMOS circuitry means that 4000 series ICs are static sensitive. Touching a pin while charged with static electricity (from your clothes for example) may damage the IC. In fact most ICs in regular use are quite tolerant and earthing your hands by touching a metal water pipe or window framebefore handling them will be adequate. ICs should be left in their protective packaging until you are ready to use them.

Gates

Quad 2-input gates
* 4001 quad 2-input NOR
* 4011 quad 2-input NAND
* 4030 quad 2-input EX-OR (now obsolete)
* 4070 quad 2-input EX-OR
* 4071 quad 2-input OR
* 4077 quad 2-input EX-NOR
* 4081 quad 2-input AND
* 4093 quad 2-inputNAND with Schmitt trigger inputs
The 4093 has Schmitt trigger inputs to provide good noise immunity. They are ideal for slowly changing or noisy signals. The hysteresis is about 0.5V with a 4.5V supply and almost 2V with a 9V supply.

Triple 3-input gates
* 4023 triple 3-input NAND
* 4025 triple 3-input NOR
* 4073 triple 3-input AND
* 4075 triple 3-input OR
Notice howgate 1 is spread across the two ends of the package.

Dual 4-input gates
* 4002 dual 4-input NOR
* 4012 dual 4-input NAND
* 4072 dual 4-input OR
* 4082 dual 4-input AND
NC = No Connection (a pin that is not used).

4068 8-input NAND/AND* gate
This gate has a propagation time which is about 10 times longer than normal so it is not suitable for high speed circuits.
NC =...
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