The following figure shows the transition between the current loop control mode and the voltage loop control mode.

In the beginning state, the board is set to 1 A of output current and 400 V of output voltage. The resistive load is set to 270 Ω. In this state, the load is attempting to draw more current than the 1 A current limit allows. This means that the output voltage is limited to 270 V and the current loop is in control.

In the end state, the board output current setting is changed from 1 A to 2 A. The increased current limit is more than the current draw of the load. This allows the output voltage to rise up to the commanded 400 V and the voltage control loop takes over.

Figure 4-10 V_IN = 400 V, V_OUT = 400 V. Resistive Load = 270 Ω (V_OUT: 100 V/DIV, I_OUT: 1 A/DIV, 40 ms/DIV, BWL = 20 MHz)