To switch between CV control and CC control, diodes are utilized to achieve an OR logic function as shown in Figure 7-1. Designing the circuit in this way allows one of the amplifiers (configured in either CC or CV mode) to dominate the feedback in the design. In this design, GND refers to the negative node at the secondary side of the switch-mode power supply.

The fixed 2.5V of the TL103Wx reference provides a stable DC voltage that is used to specify the CC current and CV voltage. One of the requirements of achieving this fixed value, however, is that the cathode of the reference must be supplied with a voltage of 2.5V or above.