In our daily lives, almost every electrical device depends on the power supply. The various functions inside these devices often require different DC voltages to operate. The traditional solution is to use a single flyback power supply combined with multiple buck-boost converters to achieve voltage supply for different functions. However, it is difficult to take into account the three aspects of efficiency, no-load power consumption and output accuracy at the same time.
More often than not, when engineers try to perform well in some of these areas, they sacrifice others. In other words, either the efficiency and output accuracy are improved, but this may lead to increased no-load power consumption and development costs, or the no-load power consumption and output response speed can be reduced, but this may make the conversion efficiency much lower. Therefore, how to strike a balance between these three key aspects, or to avoid this problem, becomes a very critical issue, and is one of the reasons why multi-output power supply design is difficult.
Power Integrations (PI) recently announced the launch of the INNOMUX-2 series of single-stage, independently regulated, multi-output offline power IC solutions. The Innomux-2 IC solves the challenges mentioned above by integrating the AC-DC and post-DC-DC conversion stages into a single chip, providing up to three independently regulated outputs with a single stage of conversion compared to traditional two-stage architectures, eliminating the need for multiple post-DC-DC conversion stages, reducing component count, reducing PCB footprint, and increasing efficiency by up to 10 percent.
The PI INNOMUX-2 series is an AC-DC power supply IC with a new IC topology that greatly improves the design of multi-output converters to meet a wide range of requirements. This series of ICs supports 15-100W output power capability, and can be configured with multiple constant voltage and constant current outputs, the constant voltage output provides independent and stable fixed voltage output, and the constant current output can be adjusted according to the load needs. The solution can provide a variety of constant voltage or constant current output combinations according to the load needs of different application environments, and each output can be adjusted independently, without considering the cross-regulation problem of traditional multi-output flyback converters.
The ICs use a single-stage conversion that eliminates the need for a two-stage transformation, reducing the number of components by 50% and avoiding the problem of efficiency degradation. In some applications, the overall efficiency of the system can be increased by up to 10 . In addition, the IC has a zero-voltage switching function, which effectively reduces the switching losses of the power switch tube, further improving efficiency while ensuring that the temperature of the IC is kept at a reasonable level.
Because each output of the IC is regulated independently, the need for a dummy load typically required for light-load regulation is eliminated, resulting in a more than 20% improvement in standby power consumption. Over the entire input voltage and load range, 1% output accuracy can be achieved, and each output can be independently fed back for control and switching operation.
The INNOMUX-2 solution can be combined with different solutions according to different application scenarios, supports a variety of power supply architectures, and even supports up to eight constant current outputs, which is suitable for home appliances, lighting, industrial appliances, telecommunications, displays and other fields.
The different model sizes in the INNOMUX-2 solution support a wide range of power levels. As can be seen from the boilerplate der-716 in the figure, the PCBA as a whole is very concise. This is due to the fact that the template eliminates the need for a DC-DC secondary transformation. The solution is now in mass production and can be designed using the PI Expert design software.
Since this scheme does not require a secondary transformation, the number of components required is small. The use of a single-stage conversion significantly improves efficiency and makes voltage regulation more accurate. At the same time, dummy loads are eliminated, which reduces the standby power consumption of the overall solution. The solution is available in a variety of models and supports a variety of CV and CC output combinations, with output power ranging from 10 to 100 watts.
The INNOMUX-2 solution integrates many of the same IC features as the traditional InnoSwitch3, including a 750V Powigan GaN switch, a zero-voltage switch (no active clamping required), and FluxLink magnetic inductive coupling. These unique functions and features have been recognized by a large number of customers in the market.
The solution is available in an INSOP package, which eliminates the need for an additional heatsink and dissipates heat through the PCB. The secondary-side master controller supports a variety of switching controls, including strobe switches, synchronous rectification drives, and switching control of primary MOS transistors, which can realize multiple working modes of DCM or CCM. Standby power consumption can be reduced to less than 30 milliwatts, and comprehensive protection features are integrated into the IC.
The InnoMux-2 IC delivers up to 100W of output power and achieves better than 3% regulation accuracy over the entire input voltage, load range, temperature, and load current transitions. The total efficiency of the power system (from AC to regulated low-voltage DC output section) can exceed 90%; The state-of-the-art INNOMUX-2 controller also manages power output at light loads, eliminating the need for dummy load resistors, reducing no-load power consumption to less than 30mW. The standby power consumption standard set by the European Powered Products (EUP) Directive is less than 300MW, which provides more available standby power for certain applications that need to perform the necessary functions.
The INNOMUX-2 devices are available in Power Integrations' thermally efficient INSOP 24 and INSOP 28 packages, which can be dissipated from the PCB, eliminating the need for a heatsink. Device options include dual-output and triple-output constant voltage (CV) models; Alternatively, one of the outputs can be dedicated to providing constant current (CC) drive, suitable for applications that power LED backlights in displays or provide fast charging for built-in batteries.
Typical applications include televisions, monitors, home appliances, networking equipment, smart home and building automation, LED emergency lighting, and industrial power supplies.