Decade counter is quite common in at this time’s electronics. Essentially the most generally out there IC CD7490 comprises a number of flip flops to transform BCD to decimal and is included as a part of bigger built-in circuits.
A BCD counter counts in a sequence of ten after which returns again to zero after the rely of 9.
Notice: Decade counter is often known as BCD Counter.
Decade Counter Reality Desk
Notice that this is only one instance of a fact desk for a decade counter. The particular fact desk for a given counter will rely on the design of the counter and the precise necessities of the applying.
Decade Counter Circuit Diagram
Principally, counters may be carried out fairly simply utilizing register-type circuits. In addition to the last decade counter, there are numerous different counters which might be additionally used commonly. Let’s have a look.
IC7490 Decade Counter
Counters in Digital Electronics
1. Asynchronous Counter
An asynchronous counter is a straightforward D-Flip flop, with the output fed again as enter. The output adjustments state for every clock enter. This creates a circuit that may retailer one bit of knowledge. This counter will increment as soon as for each clock cycle and takes two clock cycles for a transition from 0 to 1 and a transition from 1 to 0 creating a brand new clock with a 50% responsibility cycle.
2. Synchronous Counter
The clock inputs of all of the flip-flops are linked collectively and are triggered by the enter pulses. Thus, all of the flip-flops change state concurrently. A bonus of synchronous counters is that there is no such thing as a cumulative time delay as a result of all flip-flops are triggered in parallel.
3. Ring Counter
A hoop counter is a shift register with the output of 1 flip flop linked to the enter of the subsequent in a hoop. Usually, a sample consisting of a single bit is circulated so the state repeats each n-clock cycle if n flip-flops are used. It’s initiated such that solely certainly one of its flip-flops is the state one whereas others are of their zero states
4. Johnson Counter
A Johnson counter is a type of modified ring counter, the place the output of the final stage is inverted earlier than being fed again into the primary flop. The register cycles by a sequence of bit patterns, whose size is the same as twice the size of the shift register, persevering with indefinitely. It is extremely generally present in digital-to-analog converters.
5. Decade Counter
The fundamental BCD (Decade) counter is an digital circuit with a 4-bit binary output and an enter sign (referred to as a clock). With every clock pulse the outputs advance to the subsequent larger worth, resetting to 0000 when the output is 1001 and a subsequent clock pulse is obtained. Decade counters are utilized in clock circuits, frequency dividers, state machines, and sequencers, simply to call just a few purposes.
Decade Counter FAQs
Listed below are some frequent questions and solutions about decade counters:
Q. What’s a decade counter used for?
Decade counters are utilized in quite a lot of purposes the place a lot of counts are wanted, however house or energy constraints stop the usage of a bigger counter. Some frequent purposes for these counters embrace frequency division, pulse technology, and digital show programs.
Q. How does a decade counter work?
A decade counter usually consists of a collection of flip-flops, that are used to retailer the present rely. The counter increments or decrements the rely in response to a clock sign, and the output of the counter may be noticed utilizing a set of LED shows or different varieties of digital shows.
Q. Can a decade counter rely down in addition to up?
Sure, It may be designed to rely up or down, relying on the precise necessities of the applying. A counter that counts down will usually have a special fact desk than a counter that counts up.
Q. How do I reset a decade counter?
Most BCD counters have a reset enter that can be utilized to reset the rely to zero. The reset enter is usually energetic low, which signifies that it should be held at a low logic stage so as to reset the counter.
Q. Can a decade counter be cascaded?
Sure, it’s doable to cascade a number of decade counters collectively so as to rely to even bigger values. When counters are cascaded, the output of 1 counter turns into the enter of the subsequent counter within the chain, permitting the counters to work collectively to rely to larger values.
Q. What’s the most rely worth for a decade counter?
The utmost rely worth for a decade counter is set by the variety of output bits the counter has. For instance, a counter with three output bits (just like the one within the earlier instance) can rely as much as a most of two^3 = 8, earlier than it cycles again to zero.
Q. Can a decade counter be used as a frequency divider?
Sure, a decade counter can be utilized as a frequency divider by utilizing one of many output bits as a clock sign for a subsequent stage. For instance, if a decade counter is clocked at a frequency of 10 Hz, and the Q1 output is used because the clock for a subsequent stage, that stage will probably be clocked at a frequency of 1 Hz (as soon as per decade).
Q. How do I select the precise decade counter for my software?
When deciding on a decade counter in your software, you must contemplate the next components:
- Variety of output bits: The variety of output bits will decide the utmost rely worth and the decision of the counter.
- Rely route: Resolve whether or not you want a counter that counts up or down.
- Clock frequency: Think about the clock frequency and pulse width necessities of your software.
- Energy consumption: Be sure that the counter has an influence consumption stage that’s applicable in your software.
- Dimension and weight: Think about the scale and weight constraints of your software.
Q. Are decade counters out there in numerous packages?
Sure, decade counters can be found in quite a lot of completely different packages, together with through-hole, floor mount, and customized packages. The bundle you select will rely on the precise necessities of your software, such because the out there house and the kind of circuit board you’re utilizing.
Q. Are there any alternate options to utilizing a BCD counter?
There are a number of alternate options to utilizing a BCD counter, relying on the precise necessities of your software. Some doable alternate options embrace utilizing a binary counter, a ripple counter, or a programmable counter.
Benefits:
- Giant rely vary: Decade counters can rely as much as a most worth of two^n, the place n is the variety of output bits. This enables them to rely very massive values, making them helpful in purposes the place a excessive diploma of decision is required.
- Easy design: BCD counters are comparatively easy circuits that may be carried out utilizing just a few flip-flops and a few logic gates. This makes them straightforward to design and debug.
- Large availability: Decade counters are broadly out there and may be bought from quite a lot of producers.
Disadvantages:
- Restricted decision: As a result of decade counters rely in many years (multiples of 10), they might not present ample decision for some purposes. For instance, a counter with three output bits can solely rely as much as a most of two^3 = 8, earlier than it cycles again to zero.
- Restricted pace: BCD counters are usually slower than different varieties of counters, corresponding to binary counters, as a result of they use extra phases. This will make them unsuitable for high-speed purposes.
- Energy consumption: BCD counters can eat extra energy than different varieties of counters, which can be an obstacle in purposes the place energy consumption is a priority.
BCD Counter/Divider with Ten Decoded Outputs Datasheet: click on right here
For a extra detailed lesson on counters, take a look on the presentation under;
This text was first revealed on 26 August 2017 and was up to date on November 2023
