Boost converter for 5V rails from a 2.5V min input
The NXP PCA9410AUKZ is a step-up (boost) DC-DC converter delivering a fixed 5V output at up to 500 mA from an input range of 2.5V to 5.25V. With a 3 MHz switching frequency and integrated synchronous rectifier, external inductor and capacitor values stay small — the 3 MHz carrier pushes the ripple into a band where a 1 µH inductor and 10 µF output cap typically suffice, shrinking the total solution footprint.
Package and board-fit: 9-WLCSP rework reality
Housed in a 9-bump WLCSP measuring 1.24 x 1.24 mm (supplier device package 9-WLCSP), the PCA9410AUKZ requires a solder-paste stencil with aperture openings matched to the bump pitch — typically 0.4 mm pitch for this class of WLCSP. The wafer-level chip-scale package has no molded body, so the die backside is exposed; a no-clean flux residue left under the die can trap moisture and cause popcorning during reflow. A pre-bake at 125 °C for 8 hours is recommended if the parts have been exposed to ambient humidity beyond the MSL floor life.