2.2 Evaluating Loop Characteristics With Cable Compensation Function

When the cable compensation function is used, the setup shown in Figure 3 cannot cut off the loop completely. This method cannot measure the loop characteristic correctly when the cable compensation function is enabled. For this case, fast load transient is used to evaluate loop characteristics. Generally speaking, when the phase margin is greater than 45 °, the overshoot of the load transient will be smaller, and the overshoot callback will be smooth ^[1]. For poor loop design, its overshoot of load transient will be higher, and the overshoot callback may have ringing. The load transient performance of TPS2583x-Q1 is compared with and without cable compensation function. Figure 5 is the load transient result of no cable compensation function. Figure 6 is the load transient result with cable compensation function. The overshoots and undershoots are summarized in Table 1.