Boost switch delivers low switching losses

Fairchild Semiconductor is offering a high-efficiency boost switch targeting cellphones, medical, portable and consumer applications.

The FDFME3N311ZT combines a 30V integrated n-channel PowerTrench MOSFET and Schottky diode for low input capacitance (55pF typical) and total gate charge (1nC) to improve efficiency in DC/DC boost designs.

Designed with Fairchild's PowerTrench process technology, the FDFME3N311ZT delivers low switching losses through the careful optimization of dynamic characteristics. Its Schottky diode has low reverse leakage current over temperature to prevent a lowering of the converter efficiency as the package temperature rises.

The FDFME3N311ZT integrates two discrete devices into a compact (1.6mm x 1.6mm) and low-profile (0.55mm) MicroFET thin package.

In applications such as cellphones, the FDFME3N311ZT offers a 30V breakdown voltage to drive up to seven or eight white LEDs, depending on the LEDs selected and design guardband. White LEDs are typically used for display backlighting in mobile devices such as cellphones, and are normally connected in a series path to ensure a uniform forward current and brightness for each LED. With each white LED having a forward voltage of around 3- to 3.5V, this boost switch is instrumental in stepping-up the available battery voltage and in most cases, a single cell lithium type.

Pricing for FDFME3N311ZT starts at $0.25 each in 1K quantities. Samples are available now; delivery is 8 to 12 weeks ARO.

- Ismini Scouras
eeProductCenter

For application notes on boost switches click here.