JAJSMG6A April 2023 – September 2023 TPS923652 , TPS923653 , TPS923654 , TPS923655
PRODUCTION DATA
An input capacitor is required to reduce the surge current drawn from the input supply and the switching noise coming from the device. Electrolytic capacitors are recommended for energy storage. Ceramic capacitors with X5R or X7R dielectrics are highly recommended because of their low ESR and small temperature coefficients. For most applications, it is recommended to place a 10-μF capacitor along with a 0.1-µF capacitor from VIN to PGND/AGND to provide high-frequency filtering. The input capacitor voltage rating must be greater than the maximum input voltage. Use 式 16 to calculate the input ripple voltage, where ESRCIN is the ESR of input capacitor, and KDR is the derating coefficient of ceramic capacitance at the applied DC voltage.
In this design, a 100-µF, 50V electrolytic capacitor, a 4.7-µF, 100V X7R ceramic capacitor and a 0.1-µF, 100V X7R ceramic capacitor are chosen, yielding around 190-mV input ripple voltage.