The advantages and disadvantages of the switch mode power supply

[weho]

The use of any technology is often a careful balance of several advantages and disadvantages. This is true for switch-mode power supplies  which offer some distinct advantages but also have their drawbacks.

SMPS advantages

 

High efficiency

The switching action means the series regulator element is either on or off and therefore little energy is dissipated as heat and very high-efficiency levels can be achieved.

 

Compact

As a result of the high efficiency and low levels of heat dissipation, the switch-mode power supplies can be made more compact.

 

Costs

one of the points that make switch-mode power supplies very attractive is the cost. The higher efficiency and the switching nature of the design mean that the heat that needs to be reduced is lower than that of linear supplies and this reduces costs. Long with this, the switching nature of the supply means that many of the components are lower cost.

 

Flexible technology

Switch-mode power supply technology can be used to provide high-efficiency voltage conversions in voltage step-up or “Boost” applications or step-down “Buck” applications.

 

SMPS Disadvantages

 

Noise

The transient spikes that occur from the switching action on switch mode power supplies are one of the most significant problems. The spikes can migrate into all areas of the circuits that the SMPSs power if the spikes are not adequately filtered. Additionally, the spikes or transients can cause electromagnetic or RF interference which can affect other nearby items of electronic equipment, particularly if they receive radio signals.

 

External components

While it is possible to design a switch-mode regulator using a single integrated circuit, external components are typically required. The most obvious is the reservoir capacitor, but filter components are also needed. In some designs, the series switch element may be incorporated within the integrated circuit, but where any current is consumed, the series switch will be an external component. These components all require space and add to the cost.

 

Expert design required

It is often possible to put together a switch-mode power supply that works. Ensuring that it performs to the required specification can be more difficult. Ensuring the ripple and interference levels are maintained can be particularly tricky.

 

Filtering

Careful consideration of the filtering for an SMPS because the poor design can lead to high levels of noise and spikes in the output.

 

On balance, switch-mode power supplies are ideal for a host of applications from computers to chargers, and laboratory equipment to many items of domestic electronic gadgetry. Cost, size, and efficiency are critical factors in ensuring that they are the mainstay technology of very many applications.

 

Founded in 2007, Zhejiang Weihao Electronics  Co., Ltd. has long been committed to the research and development, production, and sales of new energy products. If you have any questions, please contact us at [e-mail].