The advantages of scalability: from Peter.Parker (Peter Parker) to pin multiplexing

“Under normal circumstances, when Spider-Man is looking for buildings to climb, scalability is an important factor to consider. Although the power supply design is not a typical superhero outfit, the scalability of the design is often as important as meeting the needs of the design. To achieve design flexibility, the most effective way is to choose a series of devices with scalability.

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Under normal circumstances, when Spider-Man is looking for buildings to climb, scalability is an important factor to consider. Although the power supply design is not a typical superhero outfit, the scalability of the design is often as important as meeting the needs of the design. To achieve design flexibility, the most effective way is to choose a series of devices with scalability.

The so-called expandable series of devices means that the pins of each device are compatible with each other, and the pins of each device in the series are the same, as shown in Figure 1. In other words, if you need to replace a device with a rated current of 10A with a rated current For devices with a current of 20A, you only need to remove the 10A device and install the 20A device. There is no need to reorganize or significantly change the Circuit board configuration; you can continue to use the features of the same series of devices, such as the small number of external components and the Stackability and PMBus agreement, etc. All in all, the scalability of a series of products provides a wider range of services, not just one or two applications.

Figure 1: An example of a scalable pin-to-pin device

Beep! The rated current is too high!

Using a stacked configuration in the design, scalability will be more advantageous, because high-current applications (>80 A) usually cannot be repaired with a single integrated circuit (IC). If it is stackable, multiple DC/DC conversions can be converted The converters are connected in parallel to form a multi-phase transformer solution with comprehensive output ratings. The total rated output current is the sum of the rated currents of the stacked chips. For example, if a 10A device and a 20A device are stacked, the load point can handle a current of 30A. This type of application generally requires a DC/DC controller and multiple power stages, but the stacked configuration can tie two or more transformer outputs together, reducing the overall design area. The standard architecture shown in Figure 2 uses three ICs. The stackable architecture uses only two ICs.

Figure 2: Area comparison between standard and stacked configuration

Compared to a single IC, the stacked configuration can achieve greater heat dissipation because the heat is distributed across multiple components. Stackability can also reduce costs, because the cost of low-grade inductors is lower than the cost of high-grade inductors in a single IC. You can mix and match components in an expandable series of stacks. This easily interchangeable feature can more effectively meet the point of load demand.

Power brings excellent pin reuse capability

The scalability of the DC/DC converter can reserve the number of external components when configuring components through pin multiplexing or PMBus for use when demand changes. For example, pin multiplexing allows designers to select internal compensation components by placing different resistor configurations at appropriate pin locations. Using a series of products with internal compensation and scalability, such as TPS546A24A, TPS546B24A, TPS546D24A, etc., no additional work is required, because the resistance configuration between the devices is the same. Even if the IC is eventually replaced, the pin multiplexing configuration can be simply reset.

It can be seen from Figure 3 that even if the selected configuration is changed, pin multiplexing does not necessarily increase the number of external components; when using pin multiplexing to switch between two different switching frequencies, you only need to simply change some of them resistance

Figure 3: Use two different pin multiplexing configurations to change the switching frequency of TPS546D24A

This advantage can also be extended to PMBus converters. If the success or failure of the design depends on whether it can receive fault notifications or power-good signals (PG), all series products can have these functions; for stackable PMBus compatible components, one component Acting as the main element of the stack, the sub-elements will run according to the commands received by the main element.

Save the world (or save the design process)

By expanding on the current rating, it is mixed and matched with stackability, and the number of external components is reserved, which brings more versatility through the use of expandable components. If the current pin multiplexing configuration or device does not meet the load point, just replace the resistor or switch to other components in the same series of products.

You can choose to spend a lot of time redesigning the details, or let an expandable family tailor it for you. Even Tony Stark (Tony Stark) would not redesign the arc reactor every time a new Iron Man suit is made, otherwise, how could he have time to save the world?