The recommendation for the TPS7H1121 is to utilize ceramic bypass capacitors with a tantalum bulk capacitor. The combination of a tantalum and ceramic capacitor forms a hybrid network capacitor; see application report How to Calculate the Load Pole and ESR Zero When Using Hybrid Output Capacitors (SLVAE26) for how to analytically implement and assess the applied output capacitor network.

Figure 9-3 Recommended Hybrid Output Capacitor Network Simplification

TI recommends when conducting analytical analysis of the output capacitor network to only combine capacitors and the associated parasitic parameters which are identically specified (combine identical tantalum’s, keep bypass caps and tantalum caps distinct from each other in analysis). In the figure above, capacitors C_OUT1 and C_OUT2 are combined into effective capacitance and ESR of C_eff and R_eff with the bypass cap C_BYP being excluded.