To make sure the half-bridge circuit depicted in Figure 2-11 operate within safe limits, maintain efficiency, and contribute to the circuit's longevity, selecting the appropriate MOSFETs involves several considerations:

1. Voltage Rating: The MOSFETs must have a drain-to-source voltage rating (V_DS) that exceeds the maximum input voltage (3.6V) of the circuit to handle voltage spikes without breaking down.
2. R_DS (on) Value: A lower on-resistance (R_DS (on)) is preferred for reduced conduction losses, which improves efficiency and minimizes heat generation.
3. Gate Charge: Lower gate charge (Qg) allows for faster switching and lower switching losses, which is critical for high switching frequency operation.

Besides the aforementioned characteristics, it is also crucial to factor in the threshold voltage (VGS_th), switching speed, and package. Aiming for a more compact design, a comparison of various MOSFETs with ultra-small footprints is conducted, as detailed in Table 1-2 for N-MOSFETs and Table 1-3 for P-MOSFETs.

After comparing the specifications in the tables, the CSD13380F3 for N-Channel and CSD23382F4 for P-Channel MOSFETs have been selected. This decision is based on their lower resistance when on (R_DS(on)) and the lower charge required to switch them on and off (Qg), which means they will use less power and switch faster. Additionally, both of them the threshold voltages (V_GS(th)) are very similar, which ensures a balanced switching and reduces the risk of short through during transitions, and overall leads to a more efficient circuit operation. These features make them well-suited for high-frequency, space-conscious applications.