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The 4000 series is the general classification used to refer to the industry standard integrated circuits which implement a variety of logic functions using CMOS technology. They were introduced by RCA as CD4000 COS/MOS in 1968, as a lower power and more versatile alternative to the 7400 series of TTL logic chips. Almost all IC manufacturers active during the era fabricated chips from this series.
Initially, the 4000 series was slower than the popular 7400 TTL chips, but had the advantage of much lower power consumption, the ability to operate over a much wider range of supply voltages (3V to 15V), and simpler circuit design due to the vastly increased fanout. However their slower speed (initially only capable of about 1 MHz operation, compared with TTL's 10 MHz) meant that their applications were limited to static or slow speed designs. Later, new fabrication technology largely overcame the speed problems, while retaining backward compatibility with most circuit designs. Although all semiconductors can be damaged by electrostatic discharge, the high impedance of CMOS inputs made them more susceptible than bipolar, TTL, devices. Eventually, the advantages of CMOS (especially the later series such as 74HC) edged out the older TTL chips, but at the same time ever increasing LSI techniques edged out the modular chip approach to design. The 4000 series is still widely available, but perhaps less important than it was two decades ago.
The series was extended in the late 1970s and 1980s to include new types which implemented new or more greatly integrated functions, or were better versions of existing chips in the 4000 series. Most of these newer chips were given 45xx and 45xxx designations, but are usually still regarded by engineers as part of the 4000 series.
In the 1990s, some manufacturers (e.g. Texas Instruments) ported the 4000 series to their 74HC / 74HCT series to make chips like the 74HCT4060 that offers the functionality of a 4060 IC but with the speed of the 74HCT chip.
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Design considerations
The original 4000 series was available in two versions. The A series was unbuffered, while the B series featured buffered outputs. The buffered outputs were able to source or sink more current than the unbuffered outputs, which could eliminate the need for discrete switching transistors in some designs. The buffered versions were also faster, as the signal rise time through the buffer was faster than the unbuffered chip's output transistor
The 4000 series permits the use of "cookbook" design at least for slow design, where standard circuit elements can be created and shared, and connected to other circuits with few, if any, connection difficulties. This greatly speeds up the design of new hardware by reusing standard approaches to circuit design. In contrast, TTL circuits, while similarly modular, often required much more careful interfacing, since the limited fanout (and fan-in) meant that loading of each output had to be carefully considered. Some modern TTL families, like 74LS reduce this problem with fanouts of 20. It is also much easier to prototype LSI designs using the 4000 series and get repeatable and transferrable results when moving to the more integrated design.
Some care needed to be taken with the design of circuits using these chips. Many parts offered multiple gates in a single package. Using less than the complete number of gates was common, and an engineer who forgot to tie off the other gates would find the chip using too much current. The problem was caused by biasing in each gate. With the outputs disconnected, the gate would bias itself into a linear mode where the outputs were partially switched. This left the output buffer drawing a great deal of current, since it wasn't fully on or off.
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Example common 4000 series chips
4000 - Dual 3-Input NOR Gate and Inverter
4001 - Quad 2-Input NOR Gate
4002 - Dual 4-Input NOR Gate OR Gate
4010 - hex non-inverting buffer
4012 - Dual 4-input NAND Gate
4013 - Dual D-type flip-flop with set and clear
4017 - Johnson Decade Counter with 10 Decoded Outputs
4020 - 14-stage binary counter
4023 - triple 3-input NAND gate
4024 - 7-Stage Binary Ripple Counter
4025 - Triple 3-Input NOR Gate
4026 - Decade counter with seven-segment display driver
4027 - Dual J-K flip-flop with set and clear
4069 - Hex Inverter (6 unbuffered NOT gates)
4071 - Quad 2-Input OR Gate
4072 - Dual 4-Input OR Gate
4073 - Triple 3-Input AND Gate
4075 - Triple 3-Input OR Gate
4076 - Quad D-Type Register with 3-State Outputs
4081 - Quad 2-Input AND Gate
4082 - Dual 4-Input AND Gate
4094 - 8-Stage Shift-and-Store Bus Register
4104 - Quad Low-to-High Voltage Translator with 3-State Outputs
4503 - Hex buffer (3-state non-inverting)
4511 - BCD to seven-Segment Latch/Decoder/Driver with Lamp Test Input
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Notable parts
A few parts are notable in the 4000 series because of their level of integration compared to other . This list is intentionally incomplete and is meant to provide a sample of the more interesting parts in the series.
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4017 decade counter
The 4017 IC is a 16-pin CMOS decade counter from the 4000 series. It takes clock pulses from the clock input, and makes the ten outputs come on in sequence every time a clock pulse arrives.
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Pinout
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4026 counter and display decoder
The 4026 IC is a 16-pin CMOS seven-segment counter from the 4000 series. It counts clock pulses and returns the output in a form which can be displayed on a seven-segment display. This avoids using a binary-coded decimal to seven-segment decoder, but it can only be used to display the (decimal) digits 0-9.
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Pinout
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4511 BCD to seven-segment decoder
The 4511 IC is a 16-pin CMOS BCD to seven-segment decoder from the 4000 series. It takes the binary-coded decimal from a binary counter and decodes it to drive a seven-segment display.
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Pinout
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See Also
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