PCB Power Integrity: How to Measure VCC Ripple, Noise, and Voltage Drop

Introduction A PCB may appear to have a stable power supply when measured with a multimeter. For example, you may measure: VCC = 3.30 V But this does not necessarily mean that the power rail is clean. An oscilloscope may reveal: Ripple High-frequency noise Voltage spikes Ringing Startup disturbances Voltage drop during high-current operation Switching […]