Ultra-low R/sub dson/ 12 V P-channel trench MOSFET

Abstract

This paper describes a high density trench P-channel MOSFET for portable applications. These FETs are required to have extremely low R/sub dson/ with gate drives limited by single cell Li-ion battery voltage as low as 2.5 V. This 12 V FET in an SO8 package measures only 5 m/spl Omega/ at 4.5 V/sub gs/, and 7 m/spl Omega/ at 2.5 V/sub gs/. Eliminating package and top metal resistance, this corresponds to a specific R/sub dson/ of 21.6 and 37.0 m/spl Omega/-mm/sup 2/, respectively. Typical applications for these devices include battery charging and load switching in cell phones and laptops.