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Design by Circuit Block

A real board is not one circuit — it's several blocks, each with its own layout rules. A power supply cares about loop area and heat; a high-speed bus cares about impedance and return paths; an MCU cares about decoupling and clean clocks. Designing "the whole board the same way" is how boards fail.

This section classifies the common blocks and links a focused guide for each.

Classification​

BlockWhat it handlesPrimary concernPage
MCU & DigitalMicrocontrollers, logic, memoryDecoupling, clocks, reset/boot, programmingMCU & Digital
Power supplyLDO / buck / boost regulationLoop area, feedback, thermal, noisePower Supplies
Power electronicsHigh current, motor drive, switching FETsCopper/thermal, gate drive, isolationPower Electronics
High-speed digitalUSB, Ethernet, HDMI, MIPI, DDRImpedance, length match, return pathHigh-Speed Signals
Analog & mixed-signalADC/DAC, sensors, op-ampsGrounding, placement, reference, noiseAnalog & Mixed-Signal

How to use this​

  1. Split your schematic into blocks — power tree, MCU, each interface, analog front-end.
  2. Design each block by its own rules (the pages above).
  3. Mind the interfaces between blocks — power sequencing, shared grounds, where a high-speed trace crosses a plane split, where a switching regulator sits next to an ADC.
Start from the power tree

Before placement, sketch the power tree (every voltage rail, its source, and its current). Most layout and grounding decisions follow from it.

See also​