I want to build a simple counter circuit with a 7 segment LED display. If you had
a choice between the CD4026 and the CD4033, what is the better choice? Also,
I see that some makers use 220 ohm current-limiting resistors for each segment
and some don't bother. Should these resistors be used?

juan

 

Have you looked at what the differences are between them?

Which of those differences are relevant to your goals and requirements. Let that guide you in your selection.

 

Have you looked at what the differences are between them?

Which of those differences are relevant to your goals and requirements. Let that guide you in your selection.

My goal is building a counter circuit.

 

If you had
a choice between the CD4026 and the CD4033, what is the better choice?

I'd pick something else. Those "counters" are too special purpose and I have never considered buying them. My preference now is CD4029 because it's binary or decade, up or down, with preset.

 

Instead of CD4026 or C4033, I would be considering CD4511 or even CD40110.

 

My goal is building a counter circuit.

What is a "counter circuit"?
There are many different functions and usage of a counter circuit.

 

I'd pick something else. Those "counters" are too special purpose and I have never considered buying them. My preference now is CD4029 because it's binary or decade, up or down, with preset.

They don't drive a 7 segment display.

 

and current limiting resistors for LEDS should always be used, if LEDs are not multiplexed, 5-10mA is usually fine. and resistor value is then determined based on chosen LED type and supply voltage.

and it is very easy to calculate...

R=(Vcc-Vf)/I

for example if using 9V supply and LEDs have Vf value 2.4V when drawing 8mA then
R=(9-2.4)/0.008 = 825 Ohm. nearest value is 820 Ohm

if doing the same for 5V you get
R=(5-2.4)/0.008 =325 Ohm, nearest value is 330 Ohm

if you are using old display (less bright) you may find slightly higher current work better. such as 12mA... which takes you to 220 Ohm resistors when the Vcc is 5V.

 

They don't drive a 7 segment display.

neither does 4026 which was your first candidate

 

They don't drive a 7 segment display.

Not a problem for me because I have CD4511. If you build larger counters, multiplexing can decrease component count.

I find the counters with drivers for seven segment displays to be too limiting (e.g. implementing a mod 60 counter without resorting to decoding a lot of segments). Supposedly CD4026 has a way to use the ungated C segment to do that but I don't know of anyone who has figured out how to do it.

 

CD4026 is often preferred for display applications since it is specifically designed for this purpose, integrating better with the 7-segment display functions. The CD4033 is similar but is more of a general-purpose counter. As for current-limiting resistors, it is essential to include them, typically 220 ohms for each segment, because they protect the LEDs from drawing excessive current that may lead to overheating, damage, or a reduced lifespan of both the display and other components in the circuit. For modern, high-speed, and power-efficient designs, the 74HC/HCT4017 or MC14017 variants are better alternatives to the CD4026/CD4033. They offer the same counting functionality but with improved performance and power characteristics.