请问下大家，
1.最近在选用一款降压转换芯片，留意到了TPS5420，在观看规格书的时候，不太理解输入和输出电容是如何选择的，尤其是现在市面大部分的电容没有给出ESR参数，
2.For this design example, the intended closed loop crossover frequency is between 2590 Hz and 24 kHz, and below the ESR zero of the output capacitor. Under these conditions, the closed loop crossover frequency is related to the LC corner frequency as: 规格书中，2590hz 到24Khz是如何得到的？
