High-pass filters that block DC at the input of the amplifier, at the second series stage input, and at the input of the analyzer are used to eliminate any DC offset from creeping into the amplified noise signal. The input filter has a 3Hz cutoff frequency to enable a flat enough noise measurement from such low frequency if necessary. The remaining filters have 10Hz cutoff frequencies, as required by the BW noise measurement of the LDO.

Tantalum capacitors are preferred for the filters blocking DC to the input of the amplifier, however, ceramic capacitors can be used despite the piezoelectric nature of these capacitors. In this design, ceramic capacitors are used since these capacitors maintain a neutral polarity attribute and have characteristically low ESR and ESL. This enables the use of the amplifier for both positive and negative LDOs. Placing the amplifier circuit in a vibration free, and RF immune, test enclosure can eliminate the adverse piezoelectric nature of such capacitors.