In most LDOs, the band gap is the dominant noise source. If a noise-reduction capacitor (C_NR) is used with the TPS799, the band gap does not contribute significantly to noise. Instead, noise is dominated by the output resistor divider and the error amplifier input. To minimize noise in a given application, use a 0.01-μF noise reduction capacitor. To further optimize noise, equivalent series resistance of the output capacitor can be set to approximately 0.2 Ω. This configuration maximizes phase margin in the control loop, reducing total output noise by up to 10%.

Noise can be referred to the feedback point; with C_NR = 0.01 μF total noise is approximately given by Equation 1:

Equation 1.