Summary of SWITCHMODE POWER SUPPLY TOPOLOGIES EXPLAINED
The article compares Linear Power Supplies and Switched Mode Power Supplies (SMPS), noting SMPS offers higher efficiency, smaller size, and falling costs despite greater complexity and component count. It references Microchip’s A1114 application note detailing SMPS designs and selection factors, and describes SMPS stages (rectifier/filter, inverter) and switching frequency. It also mentions Open Electronics’ Torpedo SEPIC SMPS with Input Stage, Battery Charger, and SEPIC Converter enabling seamless source transitions.
Parts used in the Switched Mode Power Supply (SMPS) Project:
- Transformer (in linear supplies context)
- Rectifier
- Low-pass filter
- Inverter
- Switching transistors or MOSFETs
- Inductors
- Capacitors
- Diodes
- Control circuitry (PWM controller)
- Battery (for Torpedo example)
- SEPIC converter stage components
The role of power supply is crucial for electronic circuits because without sufficient power, the circuit cannot function at its optimal level. On the other hand, an exceeded power supply can deteriorate the circuit components by heating effect. There are usually two choices for power supply topologies; Linear Power Supply and Switched Mode Power Supply (SMPS).
The linear power supply is traditionally an old topology, thus it had its presence in the design and architecture of older electronic components. But the new Switched Mode Power Supply topology is preferred over Linear Power Supply for current circuit designs due to its increased efficiency and compact size. However, the SMPS has more components and complex design still its advantages outweighs the linear power supply.
Also, the cost of SMPS was high initially
but with the birth of the electronic age, component costs have dropped so low that the high raw material content of copper and iron in the linear transformer has made the SMPS technology more cost-effective.
We saw the introduction of SMPS technologies by Microchip’s A1114 application note, which described the working of SMPS circuits in December 2015. The application note highlights the applications of various SMPS technologies and the design specifications of components for SMPS. It also suggests the factors for consideration while selecting SMPS topologies.
Switched Mode Power Supply Topology
As Switch Mode Power Supply contains a large number of components, thus it needs different stages. Every stage takes care of all the factors necessary for optimal performance. Example: If the input supply is AC, then the input stage has a provision of rectifier and low-pass filter for AC to DC conversion. There is also an inverter stage available for DC to AC conversion by simultaneous switching DC voltage on and off. The rate of switching decides the frequency of the AC output.
We also saw the Open Electronics’ Switched Mode Power Supply known as Torpedo, with a SEPIC configuration. Its circuit structure came with three different stages; Input Stage, Battery Charger, and SEPIC Converter. A transition from battery power to another source without interruptions was one of the unique features of the Torpedo circuit.
Read more: SWITCHMODE POWER SUPPLY TOPOLOGIES EXPLAINED
- What are the main advantages of SMPS over linear power supplies?
SMPS provides increased efficiency, more compact size, and has become more cost-effective as component costs dropped. - Why did SMPS become more cost-effective than linear transformers?
Component costs dropped while linear transformers require high raw material content like copper and iron, making SMPS relatively cheaper. - What stages are typically present in an SMPS when the input is AC?
Typical stages include a rectifier and low-pass filter for AC to DC conversion, and an inverter for DC to AC conversion. - What determines the frequency of the AC output in an SMPS inverter stage?
The rate of switching of the inverter decides the frequency of the AC output. - What example SMPS design did Open Electronics publish?
Open Electronics published the Torpedo SMPS with a SEPIC configuration featuring Input Stage, Battery Charger, and SEPIC Converter stages. - What unique feature does the Torpedo SEPIC circuit offer?
The Torpedo circuit can transition from battery power to another source without interruptions. - What does Microchip’s A1114 application note cover?
It describes SMPS workings, applications of various SMPS technologies, component design specifications, and selection factors for SMPS topologies. - Why are multiple stages used in SMPS design?
Because SMPS contains many components, different stages handle specific factors necessary for optimal performance such as conversion and regulation.
