Bode plots can be used to confirm the stability of the loop. The gain of the loop (unit: dB) is a function of frequency. Loop gain and its related aspects are introduced in the next section. Loop gain can be measured with a network analyzer. The network analyzer injects low-level sine waves into the feedback loop. As the DC voltage continues to increase, these sine wave signals complete the frequency sweep until the gain drops to 0dB. Then measure the response of the gain
All voltage regulators use a feedback loop to keep the output voltage stable. The feedback signal will change in gain and phase after the regulator passes through the loop. The stability of the loop is determined by the total phase offset at the unit gain frequency.