Post Date : Mar 08, 2023 / Last updated : Apr 06, 2023

This section explains how to decide whether to use a linear voltage regulator or a switching DC/DC converter.

First, let’s review the advantages and disadvantages of the linear voltage regulator.

Linear voltage regulator advantages

  • The design is simple, operating by only connecting capacitors to both the input and output sides.
  • Low noise
  • Few components, saves space
  • Low price
  • There are many products, making it easy to select an optimal one.

Linear voltage regulator disadvantages

  • The loss is large and the efficiency poor when there is a large difference between the input voltage and the output voltage.
  • A large amount of heat is generated when the difference between the input voltage and the output voltage is large, so measures to dissipate the heat are required.
  • Only step-down operations (lowering the voltage) are possible.

To determine whether to use a voltage regulator or a switching DC/DC converter, if the voltage regulator disadvantages can be tolerated, then selecting the linear voltage regulator is the optimum option.

The conditions for using a switching DC/DC converter are as follows.

In all other cases, using a linear voltage regulator is best.

Conditions when a DC/DC converter should be used

(a)Power supply configuration

  • A power supply configuration other than step-down (step-up, step-up/down, polarity reverse) is required.

(b)Heat related

  • A voltage regulator cannot be used due to the heat generated in the IC.
  • Overall system heat generation must be kept down.
  • It is desirable that heat countermeasure components, such as a heat sink, to lower the cost and save space used by the overall system.

(c)Loss and efficiency related

  • Reducing the voltage regulator loss is desired to increase the battery operation life.
  • Using a high efficiency DC/DC converter is required to reduce the overall power consumption of the device.
Voltage Regulator
(Linear type)
DC/DC Converter
(Switching type)
Simple to designGoodNormal
Number of parts/space savingGoodNormal
Heat generationBadGood
Battery lifeShortLong
Power supply configurationStep-downStep-down/Step-up etc