SLVS751E November 2007 – January 2024 TPS5430-Q1
PRODUCTION DATA
Using Equation 10, the minimum inductor value is 12 μH. A value of 15 μH is chosen for this design.
When using ceramic output filter capacitors, the recommended LC resonant frequency must be no more than 7 kHz. Because the output inductor is already selected at 15 μH, this limits the minimum output capacitor value to:
The minimum capacitor value is calculated to be 34 μF. For this circuit a larger value of capacitor yields better transient response. A single 100-μF output capacitor is used for C3. It is important to note that the actual capacitance of ceramic capacitors decreases with applied voltage. In this example, the output voltage is set to 3.3 V, minimizing this effect.