Output noise of some voltage regulators. Noisewise, most integrated regulators are created equally bad. If the reference can be decoupled, that has been done. But there is one clear winner: Linear Technology LT3042. The filename of the red trace reads: LT3042, 5Vout, 220 Ohms load, 22uF ceramic on input, 22uF cer. on ref decoupling, 5 times 1uF ceramic on output. Measured with 68 dB gain in front of the analyzer. Deviating from the 4.7uF output capacitance recommended in the data sheet will be punished with noise peaks.