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22 DESIGN007 MAGAZINE I JANUARY 2022 Feature Article by Celso Faia and Davi Correia CADENCE DESIGN SYSTEMS e Hubble telescope, the Cassini-Huygens mission, and other exploratory spacecra uti- lize high-voltage DC power supplies for every- thing from vidicon camera tubes and mass spectrometers to radar and laser technologies. NASA has experienced performance prob- lems with the 1.5 kV supplies because—as a 2006 report stated—"designers did not take the high-voltage problems seriously in the ini- tial design." e report cited very narrow parts parameters, electrical insulation problems in dielectrics, ceramics, bad geometries, small spacing, the use of the wrong insulating mate- rials, and thermal expansion as causes for the power supply failures. Designing a circuit that includes high-volt- ages requires a different—and much more rig- orous—approach than seen with other PCB designs. And the need for more attention increases for high-density designs. Along with High-Voltage Circuit Design Guidelines and Materials that approach, design teams also must become familiar with terminology that covers insula- tion, board materials, clearance, creepage, and altitude. Designers also should have an overall knowledge of regulations that can impact the circuit. High-Voltage Design Problem-Solving Begins With the PCB Layout All of us know that proper trace spacing in a PCB design maintains signal integrity and helps with preventing the propagation of elec- tromagnetic interference. In high-voltage PCB design, trace spacing becomes even more important. If we rightfully consider the board as a series of conductive elements, the possibil- ity of differences in potential—creating high- voltage flashover with narrow trace spacing— becomes a certainty. Along with the IPC-2221 Generic Stan- dard on Printed Board Design that establishes the design principles for interconnections on PCBs, the International Electrotechnical