Linear regulators are a great choice for powering very low powered devices or applications where the difference between the input and output is small. Even though they are easy to use, simple and cheap, a linear regulator is normally inefficient. The equation for dissipated power in a linear regulator is:
Power dissipation = (input voltage – output voltage) × load current
Switching regulators on the other hand are highly efficient and available as modular chips which are compact and reliable. Switching regulators can be further divided into isolated and non-isolated.
|Linear Regulator||Switching Regulator|
|Design Flexibility||Buck||Buck, Boost, Buck-Boost|
|Efficiency||Normally low to medium-high for low difference between VIN-VOUT||High|
|Complexity||Low||Medium to high|
|Size||Small to medium, larger at high power||Smaller at similar higher power (depending on the switching frequency)|
|Total Cost||Low||Medium to high – external components|
|Ripple/Noise/EMI||Low||Medium to high|
|VIN Range||Narrow (depending on power dissipation)||Wide|
Intersil offers a wide range of step-down (buck), buck-boost, step-up (boost) switching regulators that operate with both synchronous and non-synchronous internal switches (FETs).