TPS24712: recommended ratio of Cin:Cout?

Hi Kai,

Thanks for reaching out to us. The value of COUT depends on the down stream loads at the output of TPS24712. There is not as such any recommended ratio of CIN and COUT. However, it is a good practice to provide low-impedance ceramic capacitor bypassing of the VCC and OUT pins. Values in the range of 10 nF to 1 µF are recommended. Some system topologies are insensitive to the values of these capacitors; however, some are not and require minimization of the value of the bypass capacitor. Input capacitance on a plug-in board may cause a large inrush current as the capacitor charges through the low impedance power bus when inserted. This stresses the connector contacts and causes a short voltage sag on the input bus. Small amounts of capacitance (e.g., 10 nF to 0.1 µF) are often tolerable in these systems. When the input bus power feed is inductive, then a transient voltage suppressor (TVS) diode at the input and a 10 nF to 1 μF ceramic capacitor to bypass the VCC pin to GND are often placed.