DC-DC|Basic
Advantages vs Disadvantages, and Applications
2015.09.03
Points of this article
・With a solid understanding of advantages and disadvantages, the potential use of a linear regulator should be examined by comparing it with the switching type.
・Under suitable conditions, the linear regulator may prove to be the best choice.
The greatest advantage that the linear regulator offers is the ease of use. Because a linear regulator operates when one capacitor each is simply attached to the input and output sides, in substance little design is needed. If you must be between the two, thermal dissipation design may be more complicated than circuit design (for thermal calculations, see Subsection 1-6). Also, unlike the switching power supply, the linear regulator is free of any switching noise, having ripple rejection capability and its low voltage noise, which makes the linear regulator of choice in such noise-averse applications as audio-visual, communication, medical, and measurement devices.
On the downside, the linear regulator produces substantial loss when the voltage difference between the input and output is large. Because most of the loss occurs in the form of heat, depending on the condition under which it is used, the linear regulator generates extremely large amounts of heat. Using a linear regulator adroitly with power consumption greater than a few watts requires overcoming the heat issue. In addition, linear regulators are applicable only to step-down operations. This holds true for the case of negative voltage applications. Since confusion often arises with respect to the step-down operation of negative voltage in particular, a little discussion in this regard may be in order. Given a -5V input, a negative-voltage linear regulator cannot produce a further lower output of -12V, for example. Here, the potential declines from -5V to -12V, but the voltage increases in a negative direction from -5V to -12V, amounting to a step-up change in the negative direction. Therefore, what a linear regulator is capable of performing is an operation in which the input is -12V and the output is -5V, for example.
【Download Documents】Linear Regulator Basics
This is a hand book for understanding the basics of linear regulators, such as operating principles, classification, characteristics by circuit configuration, advantages and disadvantages. In addition, typical specifications of linear regulators, efficiency and thermal calculations are also explained.
List of articles related to the「Advantages vs Disadvantages, and Applications」
Download Technical Documents
Basic of Linear Regulators and Switching Regulators
Basic studies for linear regulators and switching regulators as a DC-DC converter.
DC-DC
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Basic
- Linear Regulator Basics
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Switching Regulator Basics
- Types of Switching Regulators
- Advantages vs Disadvantages in Comparison with Linear Regulator
- Supplement-Current Paths during Synchronous Rectifying Step-Down Converter Operation
- Operating Principles of Buck Switching Regulator
- Differences between Synchronous and Nonsynchronous Rectifying DC-DC Conversion
- Control Methods (Voltage Mode, Current Mode, Hysteresis Control)
- Efficiency Improvements at Light Load for the Synchronous Rectifying Type
- Protective and Sequencing Functions
- Considerations on Switching Frequencies
- Behavior when Vin Falls Below Vout
- Supplement-Protective Function: Output Pre-bias Protection
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Concluding Remarks
- Design
- Evaluation
- Application
- Product Information
- FAQ