7.3.2 Input Capacitor Selection

The LMZM33604 requires a minimum of 20 µF of ceramic type input capacitance. Use only high-quality ceramic type X5R or X7R capacitors with sufficient voltage rating. TI recommends an additional 33 µF of non-ceramic capacitance for applications with transient load requirements. The voltage rating of input capacitors must be greater than the maximum input voltage. To compensate for the derating of ceramic capacitors, TI recommends a voltage rating of twice the maximum input voltage or placing multiple capacitors in parallel. At worst case, when operating at 50% duty cycle and maximum load, the combined ripple current rating of the input capacitors must be at least 2 A_RMS. Table 2 includes a preferred list of capacitors by vendor.