Of the many low-dropout (LDO) regulators used to regulate voltage in electronic systems, some are specifically designed for low-noise operation. The MAX8887 low-noise LDO, for example, achieves a noise voltage of only 42µVRMS over the 10Hz to 100kHz range. Applications such as the ultra-low-noise oscillators required in instrumentation, however, require even lower noise. This application note illustrates a strategy for fulfilling this requirement: a combination of low-noise components and filtering that achieves an output noise of only 6nV/√Hz at 1kHz.