4 layers68 × 100 mm

Boards in 1 GitHub repository, designed in KiCad, that use the STR1550 by STMicroelectronics (-65℃~+150℃ 1 NPN 100 10uA 12V 200mV 500V 500mA 500mW NPN SOT-23-3 Bipolar (BJT) ROHS). See how each wires it, with its parts, size, README and files; the STR1550’s symbol, footprint and pinout are on its own page.
