JAJS249E August 2006 – January 2024 TPS5410
PRODUCTION DATA
When using ceramic output filer capacitors, the recommended LC resonant frequency must be no more than 7 kHz. Because the output inductor is already selected at 68 μH, this limits the minimum output capacitor value to:
The minimum capacitor value is calculated to be 7.6 μF. For this circuit a larger value of capacitor yields better transient response. Two output capacitors are used for C3 and C4 with a value of 47 uF each. Note that the actual capacitance of ceramic capacitors decreases with applied voltage. In this case the effective value used for the calculations is approximately 70 % of the rated value or 70 μF.