6.3 Output Capacitor

The MIC38150 requires an output capacitor for stable operation. As a μCap LDO, the MIC38150 can operate with ceramic output capacitors of 10 μF or greater. Values of greater than 10 μF improve transient response and noise reduction at high frequency. X7R/X5R dielectric-type ceramic capacitors are recommended because of their superior temperature performance. X7R-type capacitors change capacitance by 15% over their operating temperature range and are the most stable type of ceramic capacitors. Larger output capacitances can be achieved by placing tantalum or aluminum electrolytics in parallel with the ceramic capacitor. For example, a 100 μF electrolytic in parallel with a 10 μF ceramic can provide the transient and high frequency noise performance of a 100 μF ceramic at a significantly lower cost. Specific undershoot/overshoot performance will depend on both the values and ESR/ESL of the capacitors.

For less than 5 mV noise performance at higher current loads, 20 μF capacitors are recommended at LDOIN and LDOOUT.