All categories
Featured selections
Trade Assurance
Buyer Central
Help Center
Get the app
Become a supplier
(3210 products available)
In most settings, DC-DC converters operate by adjusting the voltage of a DC supply to better suit a given application. These are vital where battery supplies are used since a battery's voltage level will change as the charge level changes.
The role of a boost converter is to increase the input voltage to the required output voltage. A PWM DC DC converter is often used in battery-powered systems to get more voltage from a depleting battery, so this practice helps to ensure that even with low battery levels, the required voltage for system operations can still be achieved.
Conversely, buck converters lower the voltage to what is needed. These are frequently employed to reduce a system's battery voltage to levels required by circuit components, dynamic chargers, for example.
As the name suggests, buck-boost converters can both increase and decrease input voltage. They are useful for applications where the required output voltage can be either higher or lower than the input DC supply, depending on the operating conditions.
These are used when electrical isolation is also required, such as with certain safety-critical applications. They separate the input and output circuits while transferring power through methods like magnetic coupling.
These various types of DC DC converters employ different operational techniques and thus are chosen based on required voltage levels, load currents, efficiency needs, and the level of electrical isolation required for a given application.
The materials used in PWM DC DC converters and their overall design determine how long the converters will remain effective.
Durability is paramount for DC-DC converters operating in extreme conditions or required to have long service lives. So this durability comes as a result of carefully selecting materials, robust design, and protective measures.
Conversion circuitry: The main components of the converter include resistors, inductors, capacitors, and semiconductors, like power transistors. These power transistors can be either bipolar junction transistors or MOSFETs. These two kinds of transistors are chosen based on efficiency.
Output filtering components: Capacitors and sometimes ferrite bead filters take residual switching frequencies out of the converted DC voltage for a smooth-output.
Control circuitry: A pulse width modulation circuit controls the transistors, forming a feedback network to detect voltage levels. This control loop often incorporates operational amplifiers and more transistors.
Metals: The internal components of DC DC converters, like resistors and inductors, are usually metal. This includes copper, which is used for its conductivity, and nickel, which is in many resistors due to its resistance properties. The casing may also be metal for durability - aluminium is used in many electronics for this reason.
Silicon semiconductors: The main transistors used for switching, whether MOSFETs or BJTs, are predominantly silicon-based. These are silicon carbide and silvcon transistors that have superior thermal conductivity and electrical efficiency.
Plastics and ceramics: Internally, DC DC converter units will have capacitors. Many of these capacitors have plastic film dielectrics like polyester or polypropylene. Other components may ceramic dielectrics. The casing may also be plastic, though it's less durable than aluminium casings.
Protective coatings: Epoxy resin coatings are commonly applied to circuit boards of DC DC converters operating in harsh environments. These can even be fully potted with resin for extreme conditions. A conformal coat protects internal components from moisture.
Heat sinks dissipate heat from within the converter to maintain near room temperatures of other internal components. Without them, parts could exceed their rated lifespans.
Many DC DC converters are built to tolerate input voltage surges above normal operating conditions. This saves the unit if a battery goes rogue.
IP67 rating means it can survive immersion in water for half an hour and is also protected against dust and other solids.
Shock and vibrations from vehicles or other external forces can loosen solder joints. Rubber mounts dampen these mechanical shocks to improve reliability.
DC-DC converters find commercial use across multiple industries, thanks partly to PWM's widespread adoption. Some uses include powering electronics, energising electric vehicles, adjusting solar inverter output, and converting medical implants for constant voltage output.
Consumer electronics
The smartphone charger first steps down mains electricity, then the battery and phone circuitry, with a DC DC converter to maintain steady voltage for operations and avoid draining the phone battery. TVs, laptops, tablets, etc., use similar methods to keep their batteries and circuits energised. DC DC converters have also been found in the electronic devices' embedded systems that smooth right up to 60V DC for long-term reliability.
Automotive systems
Internal combustion vehicles have an alternator to keep the battery topped up with around 14V. Electric cars have larger batteries run by an 1800V DC DC converter that steps this down for the vehicle electronics.
Renewable energy systems
With solar power, the roof panels create undeliverable variable voltage and current DC. A DC DC converter then smooths all this out and steps it down to a constant voltage for use, with all the converted output going to a battery to be stored until needed. Wind turbine arrays also have converters like this.
Medical implants
With an internal battery or kinetic energy sources, DC DC converters keep heart pacemakers and other medical devices going for years. These converters are even fully enclosed by potted resin to protect them from bodily fluids.
In choosing a PWM DC DC converter, important things to consider are the required voltage input/output, load current, efficiency, and size. These parameters must be considered to ensure the converter selected is well-suited for the required application and will operate reliably within the desired parameters.
The first important thing is to ensure the converter can handle the expected input voltage range and output the needed voltage for the load. It is also important to choose a converter that can supply at least the maximum load current and some extra margin.
Efficiency is a major factor, particularly for battery-powered applications where more energy must be conserved. Higher efficiency means less power is wasted as heat, which may also be an important consideration. A very large converter may require additional cooling.
The size of the DC DC converter may be important in compact modern devices where space is constrained. Sometimes, additional functions like protecting circuits from overcurrent conditions are incorporated into the converter. These features may allow for a simpler and smaller system design.
Other operational characteristics to note in the converter's datasheet are the operating temperature range and behaviour under extreme conditions. Be sure the converter is rugged enough to handle the environmental conditions where it must operate. Taking these many factors into account will help in choosing the most suitable PWM DC DC converter for any given application's needs.
A: Its job is to switch the main power transistor on and off at a high frequency, routing differing pulse widths to the output stage. Essentially, the wider a pulse gets, the more energy gets transferred. Conversely, the narrower a pulse becomes, the less energy gets through.
A: Up to 97% in ideal conditions, where temperature is regulated and input/output voltages are at minimal difference. PWM techniques help reach this because switching losses are minimal compared to other conversion methods.
A: No, they only convert different DC voltages. Other circuits, like rectifiers, convert AC to DC.
A: They are used in many applications. For instance, buck converters are used in battery-powered devices to lower voltage. Boost converters increase voltage from almost drained batteries to keep devices functioning. Hybrid vehicles use more complex converters to manage a range of different voltages.
