Electronics 01
Why 100nF Decoupling Capacitors? The Impedance Math
Why is every decoupling capacitor 100 nF? Impedance plots with ESL and via inductance show what the value really does and when 1 µF is better.
pcb design
Electronics 02
How to Calculate Crystal Load Capacitors (With Stray C)
CL = C1·C2/(C1+C2) + Cstray, but which stray? Worked 18 pF example, the ppm error from getting it wrong, and the gain margin check most guides skip.