Considerations for choosing a right PoL power supply
CONTENTS
2. What are the key parameters to consider when choosing a PoL power supply?
1. What is PoL power supply？
PoL power supplies, or point-of-load converters, are used as voltage regulators in distributed power architectures(DPAs) to power microprocessors, ASICs and other digital system components.
Typically, the original power voltage is stepped down by a high-power, highly isolated DC/DC converter, and then the voltage is re-converted by the PoL power supply to power the ICs and other low-voltage loads. Since a regulated and isolated DC/DC power supply has been used at the front end, so most PoLs do not require isolated voltage regulation at this point. PoL power supplies are usually non-isolated micropower DC/DC supplies.
2. What are the key parameters to consider when choosing a PoL power supply?
The two-stage voltage conversion described above is a common design concept in power supply design because of its clear and simple design structure, low cost, and its ability to overcome the effects of high peak currents and low noise margins on the performance of high power semiconductor devices, reduce power losses due to voltage reduction, and improve voltage stability, thereby increasing the performance and efficiency of the overall system.
PoL power supplies are so important in complex electronic systems, so how do you choose a PoL power supply? It is important to consider factors such as input and output voltage range, size and efficiency. Pin compatibility also needs to be taken into account. This is explained in more detail below.
1) High-current output, high-dynamic load, high output voltage accuracy
The data processing speed of DSP, FPG, ASIC and other high-performance chips is proportional to the required current, so PoL power supplies are required to have a high current output. The chip typically switches rapidly between full-speed operation mode, standby mode and sleep mode, with its clock frequency, core voltage (Vcc) and current changing accordingly, so the PoL power supply must have a high dynamic load capacity. High-end chip ICs, especially those with low operating voltages, require very high stability of the supply voltage, so the power supply for digital systems must have high output voltage accuracy to ensure normal and stable operation of the IC.
2) Compact size
As PCB space is usually limited, PoL module power supplies have the advantage of a small layout area compared to discrete solutions. In addition, the resistance of the wires can lead to a reduction in voltage. The smaller the size of the PoL power supply, the closer it can be to the point of load, reducing the length and impedance of the wires and reducing the effects of electromagnetic interference and voltage drop, thus increasing the stability and reliability of the circuit.
3) Pin compatibility-DOSA & POLA based
POLA (Point of Load Alliance) and DOSA (Distributed Power Supply Open Standards Alliance) are two product standardization consortia in the power supply industry. Their aim is to achieve pin compatibility between DC/DC products from different manufacturers, flexible interchangeability and reduced deployment risk. Pin-to-pin compatibility means that products can be directly swapped out in the event of design changes or upgrades, avoiding the need to redesign the corresponding circuits and speeding up time-to-market.
4) Wide input voltage range
Highly isolated DC-DC power supplies in circuits typically convert mains power to 5VDC or 12VDC, so PoL power supplies are better to have a wide input voltage range to match with both 5VDC and 12VDC inputs from isolated DC/DC power supplies. Choosing a PoL power supply with a wide input voltage range also makes selection easier by accepting different output voltages from the secondary power supply.
5) Adjustable output
In a distributed power supply architecture, a PoL power supply is required at the front end of each load. High-end chips such as RAM, FPGAs, CPUs/GPUs, DSPs and ASICs have different input voltages ranging from 0.6V to 5.0V. The adjustable output of the PoL voltage makes it possible to select a PoL power supply that matches the operating voltage range of the different ICs, one for all.
6) Low ripple noise
High ripple noise in the PoL power supply may lead to errors such as misjudgments in digital systems processing high-speed pulse signals, or even system crashes.
7) High efficiency
Efficiency is also one of the characteristics that should not be overlooked when selecting PoL power supplies. A small amount of inefficiency can accumulate to a large amount and lead to serious heat production, which can affect the reliability of the system and increase the cost of using the system.
8）Future trends: digital communication
The rapid development of digital systems has given a strong impetus to the development of PoL power supplies. PoL power supplies with the ability to communicate with other devices are also called digital power supplies. Digital power supplies have the ability to set, regulate and monitor the internal parameters of the power supply with external devices using standard protocol commands such as PMBUS. With such powerful features, digital PoL power supplies are attracting more and more attention.
3. Mornsun PoL Power Supplies---Less is more
As system complexity continues to grow, board space and design time are increasingly at a premium. With integrated PoL power supplies, designers can reduce the design time on the power supply and focus on critical system units without the challenges of layout size and system reliability, thereby reducing time-to-market.
Mornsun's compact, high-efficiency 6-60A PoL switching regulators typically feature ±1% output voltage accuracy, adjustable output voltage, high conversion efficiency, fast transient response, low ripple noise and PGood, remote sense and CTRL functions. In addition, these PoL power modules have a wide operating temperature range of -40°C to +85°C. DOSA and POLA are compliant and pin-to-pin compatible with international mainstream products for flexible interchangeability.
The MORNSUN 6-16A output K12MT series is available for popular information systems. The K12MT series operates over a wide input voltage range of 4.5V to 14.4V with an adjustable output voltage (TRIM) of 0.6V to 5.5V (0.6V to 3.63V for the 16A product). In addition, it has a voltage deviation as low as ±50mV and the entire performance is integrated in a compact SMD package.
With many new systems demanding higher reliability, designs are turning to digital power supplies with PMBus technology and better performance. Digital power supplies configured with the PMBus protocol not only simplify the system's power detection function but also enable the detection and response to alarms and faults, ensuring system safety. The MORNSUN small size 40-60A PMBus PoL power supply KD12T Series offers excellent features such as remote control, PGOOD, remote compensation, clock synchronization, black box fault logging, parallel connection of up to two modules, and output voltage accuracy down to ±10mV.
The KD12T-60A digital power module can provide a maximum of 60A single output or 30A dual outputs. The module has an input voltage range of 7.5 to 14.4VDC and provides a precisely adjustable output voltage of 0.6 to 4.5VDC, which can be configured via an external resistor divider or PMBus commands. The module also includes an internal real-time compensation loop to optimize the dynamic response to match changes in load jumps.
4. Summary
With the rapid development of global communication technology, various signals and data need to be connected and interactive at an increasingly fast speed. And the advancement of digital chips for microprocessors has created increasingly complex board-level power challenges that pose multiple difficulties for design engineers. MORNSUN offers a broad range of point-of-load converters designed to provide reliable and efficient power to a wide variety of electronic systems. These PoL power supplies can help optimize circuit layout designs, significantly reduce overall design and system troubleshooting time, speed time to market, and reduce overall costs to meet these challenges.
