The following recommendations on components selection focus on the design of an efficient push-pull converter with high current drive capability. Contrary to popular belief, the output voltage of the unregulated converter output drops significantly over a wide range in load current. The characteristic curve in Figure 6-1 and Figure 6-11 for example, shows that the difference between V_OUT at minimum load and V_OUT at maximum load exceeds a transceiver’s supply range. Therefore, in order to provide a stable, load independent supply while maintaining maximum possible efficiency the implementation of a low dropout regulator (LDO) is strongly advised.

The final converter circuit is shown in Figure 9-8. The measured V_OUT and efficiency characteristics for the regulated and unregulated outputs are shown in Figure 6-2 and Figure 6-12.