Overview

Every electronic product needs power conversion, and the quality of that conversion affects both the efficiency of the product and the accuracy of the circuits it powers. Renesas supplies a broad power portfolio, from integrated step-down converters to buck-boost controllers, and BeiLuo supplies them as an authorized Renesas distributor with FAE support for power design.

Several Rails from One Input

Many systems need several rails from a single input, and a dual regulator such as the ISL78208 provides two of them from one device, which reduces the board area and the part count. Its wide input range covers the common 5, 12 and 24 volt rails, and the integrated switches remove the external transistors a controller-based design would need. The two switching loops must be kept small and separate, and the package's heat must be removed, because the two channels share the device.

Point-of-Load Regulation

A regulator placed close to its load provides a clean, local rail and reduces the effect of the trace impedance and the noise on the main rail. Point-of-load regulation is common in systems that have a distributed main rail and several sensitive loads.

Regulating Across a Moving Rail

A battery rail moves as the battery charges and discharges, and it can cross the regulated output level, where a plain buck or boost converter would drop out of regulation. A buck-boost controller such as the ISL78263 regulates across that range, so the output stays stable as the input moves. As a controller, it drives external switches, which lets the current be scaled to the load, and the switch selection follows from the current and the voltage the design must handle.

Efficiency

Synchronous operation keeps the efficiency high across the input range, which matters in a battery product where every watt saved extends the run time. The efficiency and the thermal design are planned together, because the loss becomes heat that the package and the board must remove.

Layout, EMC and Thermal

Power layout is unforgiving: the switching loop must be small to limit radiated EMI, the ground return must be solid, and the regulator must have a good thermal path. Poor layout raises loss, EMI and temperature at once. The input filter limits the conducted emissions, and the layout of the filter matters as much as its components. BeiLuo's FAE team reviews the power layout and the thermal design during design-in and can measure the result in our lab.

Why BeiLuo

We hold mainstream Renesas power ICs in regional stock and ship them with import, origin and RoHS documentation. Our engineers support topology selection, switch selection, layout and thermal design from concept through production, and we can supply samples for bench validation.

Validating the Power Design

Before production, measure the efficiency across the load range, measure the ripple and the conducted emissions, and confirm the temperatures under sustained load. These measurements decide whether the design meets its efficiency, EMC and thermal requirements, and they are cheaper to take before the board is committed.

Next Steps

Send your input, output and current requirements and we will propose a power set, confirm availability, and supply samples for validation.