JAJSH64B November 2012 – April 2019 TPS53819A
PRODUCTION DATA.
Choose an input capacitance that reduces the input voltage ripple. Equation 18 calculates the minimum input capacitance. In the example design to limit the input ripple to 240 mV, assuming all ceramic and ignoring ESR ripple, the minimum input capacitance is 27.8 μF. The input capacitor must also be rated for the input RMS current calculated in Equation 19. For this design example this current is 8.95 A with the minimum 8-V input voltage. Also, the input capacitors must be rated for the maximum input voltage.
This example uses four 1206, 22 μF, 16 V, X5R ceramic capacitors with 3 mΩ of ESR. An additional 0.1-μF capacitor is placed close to the drain of the high-side MOSFET and the source of the low-side MOSFET.