8.2.1.2.2 Input and Output Capacitor Selection

For best output and input voltage filtering, ceramic capacitors are required. The input capacitor minimizes input voltage ripple, suppresses input voltage spikes and provides a stable system rail for the device. A 10-µF or larger input capacitor is required. The output capacitor value can range from 22 µF up to more than 150 µF. The recommended typical output capacitor value is 22µF. Values over 150 µF may be possible with a reduced load during startup in order to avoid triggering the Hiccup short circuit protection. A feed forward capacitor is not required for proper operation.

Ceramic capacitor has a DC-Bias effect, which has a strong influence on the final effective capacitance. Choose the right capacitor carefully in combination with considering its package size and voltage rating. Ensure that the input effective capacitance is at least 5µF and the output effective capacitance is at least 8µF.