ZHCSGN5B March 2017 – July 2018 LP8863-Q1
PRODUCTION DATA.
Gate-drive voltage for the FET is VDD with charge pump bypassed, or about double VDD, if the charge pump is enabled. Switching FET is a critical component for determining power efficiency of the boost converter. Several aspects need to be considered when selecting switching FET such as voltage and current rating, RDSON, power dissipation, thermal resistance and rise/fall times. An N type MOSFET with at least 25% higher voltage rating than maximum output voltage must be used. Current rating of switching FET should be same or higher than inductor rating. RDSON must be as low as possible, less than 20 mΩ is recommended. Thermal resistance (RθJA) must also be low to dissipate heat from power loss on switching FET. TI recommends typical rise/fall time values less than 10 ns.