When discussing the industrial market's demand for power modules, the first things that come to mind are high functionality, superior quality, and cost-effectiveness. This is precisely the intuitive impression that Mornsun's first-generation (R1) constant voltage input power module (hereinafter referred to as constant voltage power module) gave to customers. By integrating reliability systems, proprietary innovative technologies, and automated production processes, Mornsun subsequently launched its second-generation (R2) constant voltage power module, improving product reliability and reducing operating costs. While the technology and processes accumulated from the first and second generations of products fully met customers' functional needs, they did not deliver the best customer experience.
Innovation stems from market demand and is based on satisfying customer experience. Mornsun's newly launched third-generation (R3) constant voltage power module focuses its innovation on solving industry problems and exploring what constitutes a "superior customer experience" product.
1. The industry-wide challenge of achieving balanced performance leads to a poor customer experience.
In an era focused on creating the "ultimate customer experience," the challenges are becoming increasingly severe. Traditional constant-voltage power modules employ Royer self-excited push-pull circuits. Due to inherent defects, various performance parameters can interfere with each other, making it difficult to achieve a balanced performance. During electronic design, it's challenging to optimize all aspects of performance, as shown in Figure 1. Furthermore, this circuit only offers basic functionality and lacks protection against abnormal operating conditions. In case of circuit malfunctions, this can lead to power module damage or even catastrophic consequences. Even with technological breakthroughs and the addition of some protection features in the constant-voltage R2 series, it's still insufficient to guarantee product protection under various abnormal conditions.
Figure 1
1.1 Output short-circuit protection performance vs. large capacitive load capacity
Currently, most constant voltage power supply products in the industry lack continuous short-circuit protection, which is a weakness of Royer's self-excited push-pull circuit. Mornsun's R2 series constant voltage power supply achieves a breakthrough in short-circuit protection by changing the operating mode of Royer's self-excited push-pull circuit. However, improving short-circuit protection performance directly inhibits the capacitive load capacity of the product. Therefore, it is difficult to simultaneously achieve both short-circuit protection performance and high capacitive load capacity in constant voltage power supply modules.
1.2 High Capacitive Load Capacity vs. Power Supply Start-up Capacity
In some designs, a large capacitor needs to be connected to the back end of the constant voltage power supply module to reduce ripple noise. Generally, constant voltage power supply modules have a relatively small capacitive load capacity. Taking a 1W product with 5V input and 5V output as an example, the maximum capacitive load capacity is approximately 220uF. Exceeding this limit will cause poor startup problems or even directly damage the product.
1.3 High efficiency under full load VS High efficiency under light load & Low power consumption under no-load
Power supplies on the market often emphasize full-load efficiency, but tend to avoid mentioning light-load efficiency and no-load power consumption. This is because achieving high full-load efficiency is relatively easy, but achieving high light-load efficiency and low no-load power consumption is difficult.
In some instrumentation and other applications, the power supply operates in three varying states: full load (which will be derating in actual use), light load, and no load. It is more likely to operate under light load for extended periods, therefore, its efficiency under light load must be carefully considered. If the system is battery-powered, we have stringent requirements for the overall no-load standby power consumption to improve battery life. The no-load current for constant voltage power modules is generally required to be below 10mA, while industry standards, due to technological limitations, typically only achieve 15-30mA, which cannot meet customer design requirements.
Given these challenges, is it possible to find a constant voltage power module that meets all these personalized requirements in terms of performance and has high reliability?
2. Mornsun launches its third-generation (R3) constant voltage power module.
Since the existing Royer self-excited push-pull circuit design could no longer meet the various personalized requirements mentioned above, Mornsun abandoned this circuit architecture and took a different approach, focusing on chip-based design.
After three years of IC technology development, Mornsun has launched its third-generation (R3) constant voltage power supply module, employing a self-excited circuit architecture and integrating the discrete components previously located within the constant voltage power supply module. Its advantages are mainly reflected in the following aspects:
Firstly, the IC integrates output short-circuit protection.
Power supply products without output short-circuit protection may cause damage or even burnout of components in the event of a short circuit in the system.
The R3 series constant voltage chips employ a unique short-circuit protection control technology, enabling continuous short-circuit protection across the entire product line (5/12/15/24V input). This effectively isolates the chain reaction caused by the failure and short circuit of the downstream circuit in the front-end power supply, preventing catastrophic accidents such as complete system collapse and thus improving system reliability.
Secondly, the IC integrates a soft-start function.
The Royer self-excited push-pull circuit itself lacks a soft-start function, resulting in a large instantaneous current surge during startup. This surge current could potentially damage the internal switching devices of the power module, causing an input short circuit, or even trigger a chain reaction leading to a complete system crash. The constant-voltage R3 series uses an IC with a built-in soft-start function, preventing excessive input surge current during module startup and perfectly solving the aforementioned problem.
On the other hand, from the perspective of power supply, soft start reduces the input energy required for startup because it does not require a large input current. It is particularly suitable for applications with limited energy requirements, such as explosion-proof and parallel applications of multiple power supply modules. It also reduces the power redundancy requirements of the front-end power supply, saving costs for the overall system design.
Third, large capacity load.
Generally speaking, the capacitive load capacity, starting capacity, and short-circuit protection function of a switching power supply are interconnected and mutually restrictive; improving one performance will restrict the other two.
The constant voltage R3 series utilizes innovative technology to decouple capacitive load capacity, starting capability, and short-circuit protection, eliminating mutual constraints. While significantly improving short-circuit protection and starting capabilities, the constant voltage R3 generation also substantially enhances capacitive load capacity (e.g., the capacitive load capacity of the 5V output product increases from 220uF to 2400uF), enabling normal startup in electronic load CC mode (i.e., with a very large capacitive load). As shown in Figure 2, the B0505S-1WR3 starts normally in electronic load CC mode with an external 4000uF connection.
Figure 2. Electronic Load CC Mode Startup Diagram
Fourth, it improves efficiency under light load and reduces power consumption under no-load conditions.
The constant voltage R3 series reduces losses in main switching devices and transformers across the entire load range through optimized control technology, thereby improving light load efficiency and reducing no-load power consumption.
Light load efficiency: For example, the 5V output product not only achieves an efficiency of over 83% under full load, but also maintains an efficiency of over 75% under light load (10% load). This is 20 percentage points higher than our constant voltage R2 generation product, which is known for its high efficiency under light load (see Figure 3), while also solving the temperature rise problem under light load conditions.
Figure 3. Schematic diagram comparing typical efficiency values under light load
No-load power consumption: For example, the B0505S-1WR3 achieves a no-load power consumption of only 25mW and a no-load current of 5mA, as shown in Figure 4. It is particularly suitable for energy-saving devices with extremely high requirements for no-load power consumption, such as portable devices.
Figure 4 Comparison of typical values of no-load current
Fifth, the IC integrates over-temperature protection.
The constant pressure R3 series has a built-in over-temperature protection function. In applications where the temperature exceeds the specified range, it can automatically enter a sleep state to prevent damage from high temperatures. It will automatically resume operation when the temperature drops back to the set value.
For application systems, there is an "awkward" range between the output current of a power module and the output short-circuit protection trigger point. If the product remains in this range for an extended period, it is highly susceptible to damage due to overheating caused by excessive power. With over-temperature protection, even if over-power occurs during application within this range, power supply damage can be prevented.
Taking B0505S-1WR3 as an example, we briefly list the comparison of the main performance parameters of Mornsun's constant pressure R3 series:
Performance Comparison of Gauge Pressure R3 Series Product B0505S-1WR3
Sixth, reliability has been further upgraded.
Mornsun's R2 series constant voltage circuits have gained widespread market recognition for their reliability, and the R3 series further upgrades upon this foundation. On one hand, the number of internal components has been reduced by more than 40% through integration, resulting in fewer internal solder joints. This reduces the risk of cold solder joints and missing solder joints, thereby improving the product's mean time between failures (MTBF).
On the other hand, the operating state of the Royer self-excited push-pull circuit is highly dependent on the characteristics of the components themselves. Discrete components inherently exhibit high variability, which can lead to significant variations in power supply characteristics, resulting in poor batch consistency and a negative user experience for customers. The constant voltage R3 series uses an IC-driven external circuit, which is independent of component characteristics. Therefore, the variability of the components themselves does not affect the power supply product performance, effectively improving batch consistency.
In summary, the reliability of the third-generation (R3) product has been significantly improved, giving customers greater peace of mind.
Seventh, it offers better value for money.
The R3 series constant voltage circuitry employs a chip-based design, reducing components and simplifying processes, thereby lowering assembly time and costs. This innovative cost advantage delivers to customers, meeting their demands for high cost-effectiveness.
Eighth, it has strong compatibility.
During iterative updates, customers often worry about product performance and compatibility. Mornsun's third-generation constant voltage (R3) product, while inheriting the functionality and reliability of its first and second generation products, is fundamentally compatible with the first-generation (R1) and second-generation (R2) constant voltage series. The pinout, package, and overall dimensions are completely identical, requiring no changes to the existing PCB. The third-generation (R3) constant voltage product allows customers to perfectly replace our existing first-generation (R1) and second-generation (R2) products without any concerns, as shown in Figure 5.
Figure 5 Product Compatibility Diagram
3. Summary
For 19 years, Mornsun has remained true to its original aspirations, striving for excellence to embody the spirit of craftsmanship. The newly launched R3 series of constant voltage power supplies utilizes a chip-based design, which not only improves output short-circuit protection, capacitive load capacity, no-load power consumption, light-load efficiency, and soft-start performance through decoupled balancing, but also enhances product consistency. Furthermore, the product's compatibility design facilitates system upgrades for customers. Beyond its absolute technological advantages in enhancing customer experience, the Mornsun R3 series' independently excited architecture and IC integration technology also point to a new direction for innovation in constant voltage power supply technology.
Innovation is an attitude, and even more so, a responsibility. Mornsun takes innovation as its mission, continues to drive the development of China's power supply industry, and constantly brings customers products with better experiences.
