Small size, low cost challenges for FPGA or SoC power applications

“The trend in industrial electronics is smaller board sizes, sleeker form factors and more cost-effectiveness. Due to these trends, Electronic system designers must reduce the size and cost of printed Circuit boards (PCBs). Industrial systems using field-programmable gate arrays (FPGAs) and systems-on-chips (SoCs) require multiple power rails while facing the challenges of small size and low cost. Integrating flexible power devices can significantly reduce cost and solution size for this application.

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The trend in industrial electronics is smaller board sizes, sleeker form factors and more cost-effectiveness. Due to these trends, Electronic system designers must reduce the size and cost of printed circuit boards (PCBs). Industrial systems using field-programmable gate arrays (FPGAs) and systems-on-chips (SoCs) require multiple power rails while facing the challenges of small size and low cost. Integrating flexible power devices can significantly reduce cost and solution size for this application.

Integrated flexible power devices contain multiple DC/DC converters in the same package. These DC/DC converters can be any combination of buck converters, boost converters and/or LDOs in a single package. Figure 1 is an example functional block diagram where the LM26480 includes two 2MHz high-efficiency 1.5A step-down converters and a 300mA LDO.

Figure 1: LM26480 functional block diagram

Let us illustrate the benefits of using an integrated flexible power device with an example. Imagine designing a power management system for a drone controlled by an SoC or FPGA. Figure 2 shows the four components in this system, which are perfectly matched power management ICs (PMICs).

Figure 2: Discrete vs. Integrated Power Management

Both power solutions shown produce four independent power rails that power the system’s global positioning system (GPS), input/output, core voltage, and double data rate type 3 (DDR3). Of these two options, the front-end switch-mode power supply effectively reduces the voltage of the drone battery down to the 5V supply voltage, as shown by the input in Figure 2. Discrete components can further reduce this 5V supply (as shown in option 1) or integrated devices (as shown in option 2).

Imagine using four separate devices to power this system: two LP3982 300mA single-channel LDOs and two TLV62084 2A buck converters. You can use these discrete DC/DC converters to power the system, but still require four separate active components. Considering that active components have the highest reliability issues, this may not be the best solution.

An alternative solution can use integrated flexible power devices that can provide the voltage and current capabilities expected by the system using only a single IC. As shown in Figure 2, this provides many benefits.

First, an integrated solution is 20% more cost-effective than a discrete solution. Second, the PMIC solution requires 10% less board space than the combined board space of four discrete devices. Third, integrated devices require fewer external components than discrete solutions, further reducing overall size and cost. Reliability can be improved by reducing the number of parts in the bill of materials (BOM).

Therefore, when designing systems that require multiple power rails, especially in applications that require FPGA or SoC power, consider integrating flexible power devices.