Fairchild Semiconductor is offering designers of cell phones, medical, portable and consumer applications a boost switch that provides high efficiency in boost conversion circuits.
The FDFME3N311ZT combines a 30 V integrated N-Channel PowerTrench MOSFET and Schottky diode for low input capacitance (55 pF typical) and total gate charge (1 nC) to improve efficiency in DC-DC boost designs. Designed with Fairchild's proprietary PowerTrench process technology, the device delivers low switching losses through the careful optimization of dynamic characteristics. The device's 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 (1.6 mm x 1.6 mm) and low-profile (0.55 mm) MicroFET thin package, answering the need for compact DC-DC boost designs and offering a 36 percent space savings over prior boost switch products.
In applications such as cell phones, the FDFME3N311ZT offers a 30 V 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 cell phones, 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 3-3.5 V, this boost switch is instrumental in "stepping-up" the available battery voltage and in most cases, a single cell lithium type.
Availability and Pricing
Samples are available now with delivery being 8 to 12 weeks ARO. Price (each, 1k pcs.): $0.25.