POWER


Make effi ciency matter with the right switching voltage regulator


Effi ciency is paramount when it comes to choosing the right switching voltage regulator. The ability to provide reliable power in a small format is required for today’s miniaturised devices, says Digikey


A


fundamental requirement of electronic design is the ability to generate stable voltages capable of delivering substantial quantities of current. Switching regulators are an essential component for generating stable supply voltages and for translating voltages up or down.


Switching voltage regulators can be called many things: switcher or switch, switched- mode power supply (SMPS), and DC-DC regulators or converters. Popularity continues to grow due to the advantages they offer for more effi cient high power conversion requirements, the fl exibility of stable output from a single input voltage source, and the ability to accommodate multiple output voltages of different polarities. The most common switching converter types are: •


Boost, input voltage is stepped up and conditioned for output


• • •


Buck, input voltage is stepped down and conditioned for output


Buck-boost, input voltage is stepped up or down with negative polarity option


Flyback, a type of buck-boost that also provides galvanic isolation


Fixed and adjustable linear voltage regulators


For many years, power supply designs relied on linear voltage regulators, which have proven excellent at supplying a continuous fi xed voltage output. There are other linear voltage regulators, like the LM317, that


are adjustable.


Popular fi xed and linear output voltage regulator types are the 78xx positive output and 79xx negative output voltage series. These voltage regulators produce stable output ranging from 5 V to 24 V. Linear voltage regulators are not switched mode power supplies. Voltage regulators have the advantage of simplicity and low cost. They typically have a power output under 10 W, tend to be less effi cient, thereby generating heat, and have low noise and ripple characteristics.


Linear regulators only have step-down voltage regulation, whereas an SMPS can provide step-up and step-down and negation of the input voltage using buck, buck-boost, and boost components.


Switched mode power supply systems


Most modern televisions, personal computers, DC motor drives, and power amplifi ers require an advanced and effi cient SMPS, which utilises semiconductor switching techniques instead of standard linear methods for providing output voltage. The basic switching converter consists of a power switching stage and a control circuit.


By having lower power dissipation, SMPS has the advantage of higher effi ciency by internally switching a transistor (or power MOSFET) between the saturated “ON” and the cut-off “OFF” states.


Fig 2: Lower voltage needs can be accommodated with a BD9E105FP4-ZTL buck switching regulator


14 MAY 2025 | ELECTRONICS FOR ENGINEERS


Buck switching regulators Rohm Semiconductor’s BD9x series provides designers with high-effi ciency DC-DC buck converters, a compact option for applications requiring effi cient power conversion, including automotive and industrial designs. The BD9x series features a simplifi ed design with a reduced component count that saves space and streamlines the manufacturing process. Their low standby current allows for battery life to be extended in portable applications while maintaining stable output voltage for reliable performance, like the BD9A201FP4-LBZTL Buck Switching Regulator (Figure 1).


Fig 1: The


BD9A201FP4-LBZTL Buck Switching regulator provides stable output voltage


The BD9E105FP4-ZTL Buck Switching Regulator (Figure 2), which features a single, adjustable output, is a direct current regulator specifi cally designed for lower voltage needs. With low on-resistance power MOSFETs and a single synchronous buck DC/DC converter, the BD9E105FP4-ZTL regulator provides top effi ciency in light-load conditions. This is ideal for devices and equipment that demand minimal standby power consumption. Featuring a good transient response, it offers a small footprint on the PCB while delivering high power density in a small package, perfect for home appliance products like refrigerators and air conditioners, telecommunication devices, adaptors, and secondary power supply equipment.


Boost switching regulators The MP3414AGJ-Z Boost Switching Regulator has an adjustable output and its thin profi le is conducive for a surface mount application where space is limited.


It is easily able to perform in a temperature range of -40°C ~ 125°C and can start to operate from an input voltage as low as 1.8 V while providing inrush current and output short-circuit protection (SCP).


The ability to operate in synchronous current mode while maintaining high effi ciency is necessary when requiring a step-up converter with output disconnect. Also, there is no need for an external Schottky diode, as the effi ciency has been improved with an integrated P-channel synchronous rectifi er. The feature for output disconnect when the MP3414A shuts down allows for a complete


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42