Tip 4: Steering IC place and also bottom side PCB design

If the steering IC has integrated entrance drivers, it ends up being important to locate the IC as close as possible to the power MOSFETs. The gate driver traces that run from the IC to the MOSFETs are kept as brief and also straight as feasible to reduce parasitical gate inductance.

On a single-sided PCB design, the only option is to position the steering IC on the top (part) side of the PCB close to the power tools. However, accomplishing brief gateway drive links is typically made complex by the power stage format (specifically if even more than 2 MOSFETs are required, as in the 4-switch buck-boost, multi-phase buck or increase, and full-bridge converters). The necessary signal-level elements, attaching traces as well as vias that usually border the IC also make its positioning harder. It is often advantageous in a two-sided layout to put the IC under (solder) side of the PCB. This helps gateway drive circuit efficiency as well as shields delicate analog circuits from changing noise as well as high operating temperature levels characteristic of power devices. Number 2 shows this technique for the bottom side layout.

Number 2: Bottom layer of PCB (layer 6) watched from listed below. Small-signal parts surrounding the steering IC are located on a different ground (GND) island.

Higher-profile electrolytic capacitors are positioned on the bottom side for three reasons. They are of similar elevation to the banana links for the power terminals in this design and, thus, impose no height charge. Second, they conduct low- to mid-frequency existing harmonics [9], making extremely close placement to the MOSFETs superfluous. Third, air movement shadowing from the electrolytic capacitors is greatly inconsequential, as the lower-profile, heat-dissipating MOSFETs are sited on the leading side of the PCB.

The noise-sensitive small-signal elements for the compensation network, feedback resistors, frequency established resistor, soft-start capacitor and also current sense filter lie near their corresponding pins (COMP, FB, RT, SS, CS, CSG) and have a committed analog ground (AGND) plane that ties to the IC’s AGND pin. Power ground (PGND) connects to the subjected pad of the IC with thermal vias to inner ground airplanes. PGND attaches to AGND in your area there as well for single-point grounding.


Reducing converter losses is an essential requirement to enable compact awareness and an adaptable implementation of the converter within the intended system. Thoughtful placement and also layout of the power stage components in a PCB design allow better changing performance, higher performance, lower operating temperature levels and lowered broadband EMI for less complicated regulative conformity [8]

Keep tuned for component 3 of this collection, when I’ll dig right into the detail of routing essential traces for gate drives, result voltage comments as well as existing sense, as well as lastly ground monitoring, in tandem with a polygon plane design of the outer as well as inner layers of the multilayer PCB.

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