What are the Types of Voltage Regulators, and How do they work?

When you need a stable and reliable voltage, a voltage regulator is your go-to device. These devices produce a fixed amount of Voltage regardless of the input voltage or load current changes.  In turn, this helps to protect your electrical components from a sudden change in Voltage or frequent electricity fluctuation.

How Do Voltage Regulators Work?

Voltage regulators work by automatically creating and maintaining a constant voltage output level regardless of input voltage or load current fluctuation. These systems ensure that the power supply voltage stays within a range that matches your electrical equipment power requirements.

For the most part, voltage regulators are designed to perform DC/DC power conversion. However, some AC/AC and AC/DC voltage regulators are available in the market.

In this article, we will concentrate on DC/DC voltage regulators.

Types of Voltage Regulators

Voltage regulators fall under different categories based on their applications, power conversion mechanism and the Voltage at which they operate. There are two broad types of voltage regulators. They include;

·         Linear regulators

·         Switching regulators

1. Linear regulators

Linear regulators are mainly step-down converters because they produce a lower output voltage compared to the input voltage. To do so, linear regulators use an active pass device controlled by a high-gain operational amplifier

Compared to other types of regulators, linear regulators are cost-efficient, simple to design and reliable.

2. Switching regulators

Switching regulators can be step-down or step-up converters or a combination of the two hence more versatile than linear regulators.

These kinds of regulators are challenging to design than their linear counterparts. You’ll also need to properly tune and select the correct values depending on your components for increased stability.

Some benefits of switching regulators include supporting wider Voltage IN/ Voltage OUT applications, improved thermal performance, higher efficiency of up to 95%, and helps to keep a higher current.

Switching regulators require extra components to operate. Some of this equipment includes capacitors, inductors and FETs.

Drawbacks of Voltage Regulators

Linear regulators have low efficiency because they lose some electrical energy in the form of heat. For instance, a 5V input voltage linear regulator with a 3V output voltage ends up with a drop of 2V, meaning it’s limited to an efficiency of 3V/5V (60%). As such, you should avoid using larger input voltages as they can lead to high power dissipation and, therefore, overheating which can damage components.

Also, linear regulators are limited to step-down conversion, unlike switching regulators that can be used for both step-up and step-down conversions.

Similarly, switching regulators have their limitations, which include; are highly complex, large and produce a lot of noise.

Switching Topologies

Linear and switching regulators have several topologies. Some common topologies include; step-down, step-up and buck-boost converters for switching regulators and low-dropout topologies mainly used for linear regulators.

1. Low-dropout (LDO) regulators

LDO is among the common topologies for linear regulators. LDO works best when there’s a lower difference between the input voltage and output voltage.

2. Step-Down and Step-Up Converters

Also called buck converters, step-down converters allow high input voltage and produce a small output voltage.

Step-up converters, on the other hand, are referred to as boost converters and work by taking in lower input voltage and release a higher output voltage

3. Buck-Boost Converters

These converters combine the functionality of step-down and step-up converters. As such, they are used in most components.

Applications of Linear and Switching Regulators

Linear regulators are generally used in low current and noise-sensitive components. These regulators also work best in components with limited space or where designers need to cut costs such as headphones and wearables.

Switching regulators are primarily used where efficiency and performance are a priority. Some of these applications include industrial, automotive, consumer and enterprise applications.

Basic Parameters for a Voltage Regulator IC

The basic parameters for a regulator include;

·         Input voltage

·         Output voltage

·         Output current

The above parameters are vital in determining the type of VR topology that works best with your IC. Other parameters to consider include; switching frequency, quiescent current, feedback voltage and thermal resistance.

Selecting the Right Voltage Regulator

When selecting the proper voltage regulator, you must consider your critical parameters, such as the Voltage in, Voltage out and Input out. In addition, you must consider the system priorities such as price, and performance to name a few.

Once you’ve your specifications, you can use a parametric search table to help you find the suitable device that meets your requirements.

Need help in finding the perfect Voltage Regulator? No need to look further! EP-Power and Advanced Energy’s HiTek Power and UltraVolt product lines feature hundreds of units, options, and accessories to meet your application needs.

For enquiries, you may send us an email at: sales@edac.com.sg or give us a call at +6564547877.