PCB Blog - Layout PCB power supply regulator

A power supply regulator is a power circuit or device that can automatically adjust the output voltage. Its function is to stabilize the power supply voltage that fluctuates greatly and does not meet the requirements of the electrical equipment within its set value range so that various circuits or electrical equipment can work normally at the rated working voltage.

PCB power supply regulator 

PCB design is a crucial step in the design of switching power supplies, as it has a significant impact on the performance, EMC requirements, reliability, and producibility of the power supply. With the development of electronic technology, the volume of switching power supplies is getting smaller, the working frequency is also getting higher, and the density of internal devices is also getting higher. The requirements for PCB layout and wiring are becoming more and more strict, reasonable, and scientific PCB layout will make your homework twice the result with half the effort.

The PCB supply power regulator consists of a voltage-stabilizing circuit, a control circuit, a servo motor, etc. When the input voltage or load changes, the control circuit samples, compares, amplifies, and then drives the servo motor to rotate, thereby changing the position of the voltage regulator carbon brush. By automatically adjusting the coil turn ratio, the output voltage remains stable. The voltage regulator with a larger capacity also operates based on the principle of voltage compensation.

The main function of the power supply regulator is to

1. Adjust the output voltage of the generator

2. Prevent excessive charging of current

3. Cut off the charging circuit when reverse current occurs, and the relay will quickly cut off the charging circuit when reverse current occurs. Regulators are divided into analog regulators and digital regulators. A controller that compares the measured values of production process parameters with the given values, generates an output signal according to a certain regulation law, and drives the actuator to eliminate the deviation, keeping the parameters near the given value or changing according to a predetermined law, also known as a regulating instrument.

Characteristics of PCB power supply regulator

1. Small size and lightweight:

The volume and weight are 1/5-1/10 of the thyristor PCB power supply regulator, making it easy for you to plan, expand, move, maintain, and install.

2. Good energy-saving effect:

Due to the use of high-frequency transformers, the conversion efficiency is greatly improved. Under normal circumstances, the efficiency is increased by more than 10% compared to thyristor equipment, and when the load rate is below 70%, the efficiency is increased by more than 30% compared to thyristor equipment.

3. High output stability:

Due to the fast response speed (microsecond level) of the system, it has strong adaptability to changes in grid power and load, and the output accuracy can be better than 1%. The switching power supply has high work efficiency and control accuracy, which is beneficial for improving product quality.

4. The output waveform is easy to modulate:

Due to its high working frequency, its output waveform adjustment has a relatively low processing cost, making it easier to change the output waveform according to user process requirements. This has a strong effect on improving work efficiency and improving the quality of processed products at the workplace.

PCB supply power regulator layout guide

PCB power supply, also known as circuit board rectifier, has two prominent requirements: high reliability and high uniformity of the coating. The PCB power supply regulator adopts a brand new power operation and monitoring circuit, with a large amount of redundancy, which can ensure the reliable operation of the power supply.

For power supplies and PCBs with onboard regulators, the switch regulator layout will be the main determining factor for the overall system performance. The layout determines sensitivity to electromagnetic interference (EMI), thermal behavior, power integrity, and safety. A good layout ensures efficient power conversion and transmission to the load while allowing heat to be transferred from the thermal components in the layout and ensuring low noise coupling around the electronic system.

Try to maintain low EMI by correctly defining grounding, placing short wiring in the PCB layout, and placing current isolation parts in PCB to avoid noise coupling.

If there is noise in the layout, envelope tracking and other functions are required, or specific noise sources cause problems in the design, appropriate input and output EMI filter circuits should be used when needed. Use a large amount of copper to provide a cooling path away from important components. If necessary, you can consider a unique shell design, as well as a heat sink or fan on the thermal components. Place fast switches and high-current circuits so that there are no parasitic oscillations in the design during switching events.

The first switch mode PCB power supply regulator layout guide to consider is how to define grounding in the layout. When designing a switch power circuit, remember that there are five grounding points. These can be divided into different conductors to ensure current isolation. These are: input high current source ground, input high current circuit ground, output high current rectification ground, Output high current load ground, and low-level control ground.

Each of these grounding connections may exist in physically separate conductors, depending on the need for current isolation in converter, rectifier, or regulator circuits. If the grounding is capacitively coupled, your power circuit may allow for common mode noise, such as through nearby conductive shells.

Each high-current grounding is used as a branch of the current circuit, but its layout should provide a low-impedance return path for the current. This may require multiple through holes to return to the ground plane to allow for a high current with low equivalent inductance. These points and their potential relative to system ground become points for measuring the DC and AC signals conducted between different points in the circuit. Due to the need to prevent noise from high-current AC grounding from escaping, the negative terminal of the appropriate filter capacitor is used as the connection point for high-current grounding.

The best practice for defining ground areas is to use large flat or polygonal pouring. These regions provide low impedance paths to dissipate noise from DC output, and they can handle high return currents. They also provide a path for transferring heat from important components when needed. Placing grounding layers on both sides can absorb radiated EMI, reduce noise, and reduce grounding loop errors. At the same time as being used for electrostatic shielding and dissipating radiated EMI in eddy currents, the grounding layer also separates the power cord and power layer components from the signal layer components.

The grounding area in the design can be given multiple names based on its function. Be careful when defining grounding areas in the design and ensure that they are correctly linked together. The ground plane is also important in systems outside of the power PCB layout. Ensure that the connection is defined as having low impedance without affecting the assembly.

In the design of power supply regulators, PCB layout design is a crucial step that has a significant impact on the performance and reliability of the power supply.