SLVS350J October 2002 – May 2019 TPS795
The TPS795 uses a start-up circuit to quickly charge the noise reduction capacitor, CNR, if present (see Functional Block Diagrams). This circuit allows for the combination of very low output noise and fast start-up times. The NR pin is high impedance so a low leakage CNR capacitor must be used; most ceramic capacitors are appropriate for this configuration.
For the fastest start-up, apply VIN first, and then drive the enable pin (EN) high. If EN is tied to IN, start-up is somewhat slower. To ensure that CNR is fully charged during start-up, use a 0.1-µF or smaller capacitor.