Demystifying Switching Regulators In Power Electronics
May 02, 2024
Blog
Switching regulators are common in modern electronic devices due to their ability to provide stable and efficient power compared to linear regulators. Their efficiency comes from the switching element operating in two distinct states, fully on, or completely off. This minimizes power dissipation within the regulator itself, achieving upwards of 95% efficiency.
Furthermore, this minimal power loss translates to several advantages for engineers. Firstly, switching regulators can utilize smaller form factor components due to the reduced heat generation. Secondly, this reduction in thermal dissipation translates to less complex thermal management solutions within the overall system design.
An additional benefit of switching regulators lies in the ability to leverage the energy stored within the integrated inductor. This stored energy not only contributes to overall efficiency but can also be manipulated to create desired output voltages. This characteristic proves particularly advantageous in applications requiring multiple voltage levels or electrical isolation from the input power source.
Switching regulators consist of a transistor (which works as a switch), a control block, and a low-pass filter.
Figure 1: Block diagram of a switching regulator
In these regulators, the switch manages the unregulated input voltage supplied to the output voltage, Vout, by rapidly switching a power transistor on and off. This switching action allows for efficient energy transfer, minimizing power loss and maximizing efficiency.
The Versatility of Switching Regulators
In many industrial applications, a DC converter is a source to power different electronic circuits. It is used to step up (convert into a higher voltage level) or step down (convert into a lower voltage level) DC voltage.
A step-up switching regulator is also known as a boost converter. If the switch is in parallel and placed after the inductor, then this is a step-up converter. It increases the output voltage level relative to the input voltage, achieving this by storing energy in an inductor during the ON state of the switching transistor and releasing it to the output during the OFF state. This allows the output voltage to be higher than the input voltage. They are commonly used in battery-powered devices.
Figure 2: Simple boost (step-up) converter
A step-down switching regulator is also known as a buck converter. If the switch is in series with the input and an inductor, then this is a step-down converter. It reduces the output voltage level relative to the input voltage. It operates by continuously switching the input voltage across an inductor and then transferring it to the output capacitor, effectively stepping down the voltage. Step-down converters are widely used in applications where the input voltage is higher than the required output voltage like portable chargers.
Figure 3: Simple buck (step down) converter
An inverting switching regulator is also known as a buck-boost converter. If the switch is in series with the input and an inductor is a shunt component, then this is the circuit of a voltage inverting regulator. It can produce an output voltage that is either higher or lower than the input voltage, depending on the configuration.
Figure 4: Simple Buck-Boost (inverting) converter
Choosing the Perfect Switching Regulator: Key Considerations
Input Voltage:
The input voltage range refers to the acceptable or tolerable range of input voltages supported by the regulator.
Output Voltage:
The output voltage range refers to the constant that the voltage regulator maintains. It is important to keep output voltage falls within the specified ranges. If you are looking for a power supply for a variety of applications, consider adjustable output regulators. It allows for easy adjustments to accommodate various output requirements.
Output Current:
The current rating of a regulator (or any other circuit) reflects its capacity to deliver current at its output. The rated current of a switching regulator should be greater than the maximum load current. For instance, if your circuit operates at 15V and 60mA, it is advisable to select a power supply with a current rating above 100mA.
Temperature:
It is necessary to operate within the specified temperature range. This range is specified within data sheets. Excessive heat or extremely cold conditions can cause malfunctions and even failure.
Switching Frequency:
Frequency is a fundamental property of these circuits, representing the rate at which the transistor switches on and off. Generally, selecting the right frequency involves a trade-off between efficiency, size, cost, EMI/EMC considerations, and many other factors. For example, higher frequencies generally result in higher efficiency due to reduced switching losses, but they also make the design more expensive and compact. Conversely, lower frequencies make the design bulkier but more economical.
Features and Specifications of MicroPower Direct’s Switching Regulators:
MicroPower Direct offers a comprehensive selection of high-performance switching regulators to satisfy your design needs. These regulators boast impressive efficiency ratings of up to 95%, achieved through a minimized on-state resistance and low switching losses. The compact SMT package allows for space-saving designs, while the wide operating temperature range of -40°C to +85°C ensures reliable operation in harsh environments. For design flexibility, these regulators are available in both through-hole and surface mount configurations. Adjustable output voltage and remote on/off functionality provide further control over your power delivery system. Notably, all these features come at a competitive price point, making them an excellent choice for cost-conscious engineers.
|
Model Number |
Input Voltage Range (VDC) |
Output Voltage Range (VDC) |
Output Current (A) |
Package |
|
4.75 – 36 |
3.3 – 15 |
500 m |
SIP |
|
|
4.75 – 36 |
6.0 – 36 |
1000 m |
SIP |
|
|
4.75 – 36 |
3.3 – 15 |
500 m |
SIP |
|
|
6.00 – 36 |
3.3 – 15 |
1.0 |
SIP |
|
|
6.00 – 36 |
3.3 – 15 |
2.0 |
SIP |
|
|
9.00 – 90.00 |
3.3 – 24 |
500 m |
SIP |
|
|
4.5 – 36 |
15 – 30 |
500 m |
SMT |
|
|
4.75 – 36 |
3.5 – 36 |
1.0 |
SMT |
|
|
4.75 – 36 |
1.5 – 12 |
1.0 |
SMT |
|
|
4.75 – 36 |
1.5 – 15 |
500 m |
SMT |
|
|
8.30 – 14 |
0.75 – 5.0 |
10.0 |
SMT |
|
|
8.30 – 14 |
0.75 – 5.0 |
6A |
SMT |
|
|
8.30 – 14 |
0.75 – 5.0 |
16.0 |
SMT |
Our range of switching regulators include step-up, step-down, and inverting regulators, offering optimal efficiency and performance, and ensuring seamless operation in even the most demanding industrial environments.
For more infomation, visit embeddedcomputing.com/technology/analog-and-power/improving-applications-with-highly-efficient-power-solutions, micropowerdirect.com.
