What is a Digital Potentiometer IC? The Complete Guide

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A potentiometer is also classified as a type of variable resistor that has a third adjustable terminal. This terminal is adjusted to give the value of the potential difference across the circuit.

Potentiometers in most applications are used as measuring instruments. They are also known as voltage dividers since they measure the voltage across different points in an electric circuit.

What about digital applications? Well, this is where the essence of digital potentiometers comes in.

Digital applications make it necessary to get digital potentiometers, also classified as a type of digital resistor.

Are you planning to buy a digital potentiometer chip? This is a perfect guide for you. We are going to discuss everything that you should know about it.

By the end of the guide, you will be in a perfect position to choose the right digital potentiometer IC from the best suppliers.

What is a digital potentiometer?

As we have defined, potentiometers are types of variable resistors. Just like other types of resistors, they are also used for regulating current and voltage in electric circuits.

Perhaps you have mostly interacted with mechanical potentiometers. They allow users to manually control their resistance values.

For the digital potentiometer, things are slightly different.  Changing the resistance is done automatically. This means that there are no knobs or any other control device that you will use to change the resistance of the device.

A digital potentiometer can either be volatile or non-volatile.

A volatile potentiometer comprises resistor arrays and other electronic components such as switches, digital multiplexers, data converters, and logic gates. It is referred to as volatile because it does not retain data.

The non-volatile potentiometer is named so because it can retain some memory even after the power has been switched off. Its memory storage is in the form of EEPROM (erasable electrical programmable memory).

As we have said, digital potentiometers also serve as measuring instruments. In this case, the capacity to retain data is a major advantage. It means that you can read the measurements even after the power has been turned off.

If you are building a digital application and would like to automatically regulate current and voltage, then you should consider getting digital potentiometers.

Working principle of a digital potentiometer

A digital potentiometer is made of different components that work together to achieve a specific goal. Let’s look at each of these components and what they do.

Series of resistors

A digital potentiometer comprises a series of resistors connected forming a ladder-like structure. Each ladder has a switch that is connected to the output terminal of the potentiometer.

The series of resistors is responsible for giving the circuit the required resistance. You can get the resistance value by calculating the number of steps that make up a ladder structure. The higher the number of steps, the more the resistance value. 

Memory unit

Digital potentiometers have a form of memory module that is responsible for storing data that is generated by the device.

Most potentiometers have volatile memory units though some have non-volatile memory.

For the volatile ones, they can store memory as long as the potentiometer is connected to the power. Once you turn off the device, they will lose the data.

For the non-volatile memory, they can retain data even after disconnecting power from the IC. These potentiometers are embedded with an EEPROM IC that performs the function of memory storage.

Data storage is an important attribute that you should pay attention to when buying digital potentiometers.  You should even compare the memory capacity of different potentiometers and choose one that has the potential to deliver the best results.

Control unit

 Like most variable resistors, digital potentiometers allow users to control the operation and performance of a resistor. This is where the importance of a control unit comes in.

In analog potentiometers, there is a knob that allows users to determine the performance of the resistor.  Things are slightly different in digital potentiometers.  Here the control process is automated.

The control unit of a digital potentiometer is directly connected to the microprocessor of the device. It gets signals from the microprocessor. Usually, these signals are used for varying the resistance of the potentiometer.

 The potentiometer IC is responsible for signal management and processing to determine whether to raise or lower the resistance of a device.

The control unit also has a series bus that serves as the interface between the microprocessor chip and the control unit.

Some potentiometers have front panel switches or control logic systems that make up the control unit of the device.

Advantages of digital potentiometer ICs

Digital potentiometer ICs are mainly used in applications where external conditions are likely to affect the operations of analog potentiometers.

The robust design and build of these chips ensures that they can withstand harsh conditions such as dust and mechanical forces such as vibrations.

These semiconductor chips are quite accurate.  They can detect slight variations of current or voltage and they will send relevant signals.

Application of potentiometer ICs

Common application areas of potentiometer ICs include:

· In LEDs to change the brightness

· Adjusting the volume of audio systems

· Controlling resistance of analog circuits

· Adjusting the calibration of electronic instruments 

Conclusion

We have covered all the essential information about digital potentiometer ICs.

These are just like normal potentiometers only that they are not mechanically operated. The mechanical action of a potentiometer is replaced with digital operation.

They rely on digital signals to deliver their functions and performance.

 I hope that at this point, you are in a perfect position to buy and deploy the right digital potentiometer for your application.

Once you have the right information, the next course of action is to consider where to buy digital potentiometers.

The best place is from reliable electronic component suppliers in China. They stock a wide range of products including digital potentiometers.

 For example, we at ICRFQ are fully committed to helping our customers get the right digital potentiometers for their electronic applications.

We are ranked among the best electronic component distributors in China based on the quality of products that we supply and also services that we give.

Additionally, we have more than two decades of experience in this field.

Do not hesitate to contact us for the bulk purchase of digital potentiometers in China. We will deliver the products regardless of your location. 

Frequently asked questions about digital potentiometers

Let’s review some of the most asked questions about digital potentiometers:

What is the function of a digital potentiometer?

Digital potentiometers perform the same role as mechanical potentiometers-controlling and limiting signals in electric circuits.  These potentiometers ensure that only the right electric current gets to the target load.

What is the main advantage of a digital potentiometer over an analog potentiometer?

Digital potentiometers are getting more popular than their analog counterparts because of several reasons.

Compact and robust designs of digital potentiometers are one of the reasons. They are easy to handle and use in different application areas.  They are even applicable to miniaturized devices.

Performance is another reason behind the popularity of digital potentiometers. The robust design of these devices ensures that they can still deliver reliable performance in different application areas.

We cannot ignore the flexibility that comes with using digital potentiometers. Well, size and design are among the top reasons why they are flexible. Furthermore, the fact that these potentiometers are settable means that you can set them to get a predetermined output. It is also possible to get a digital potentiometer that is customized to meet the specific needs of your application area.

What are the most common failure modes of digital potentiometers?

Like most digital devices, the latch-up condition is the most common failure mode of digital potentiometers. The condition occurs at the terminal of the potentiometer and is characterized by a low-impedance path that is created between the supply terminal and the ground terminal. It is caused by a trigger current due to a power surge at the voltage source. 

What are the configurations of digital potentiometers?

Digital potentiometers come in two main configurations: two-terminal configuration and three-terminal configuration.

When designing an electric circuit or even an application, it is important to pay attention to the configuration of a digital potentiometer.  Similarly, you should choose the right configuration of your potentiometer even after you are done with designing the circuit.

Does switching the potentiometer on and off refresh its memory?

No. Switching a digital potentiometer on and off does not have an impact on the main memory of the device. Instead, this action only affects the register logic system of the potentiometer.

Digital potentiometers rely on the EEPROM which can retain data for up to 10 years. Also, the retention rate of EEPROM is not affected when you turn the memory on and off.

 What is the importance of operating range voltage in designing digital potentiometers?

Safety is the main reason why you should pay attention to the operating voltage range of a digital potentiometer.

Since digital potentiometer ICs regulate current, a voltage range will ensure that only the required current passes through the circuit to the load.