San Jose, Calif.Renesas Technology America Inc. has developed a dual-type power MOSFET that enables smaller, higher-efficiency synchronous-rectification DC/DC converters for generating various supply voltages in communication devices and laptop PCs.
The advanced, tenth-generation device dubbed the RJK0383DPA integrates high-side and low-side power MOSFETs and a Schottky barrier diode in a compact (5.3-6.2-0.8mm, max2) package with high thermal conductivity. In a synchronous-rectification circuit converting a 12V DC input to a 1.1V DC output at 600 kHz switching frequencies, it achieves an efficiency rating of 91.6 percent.
The RJK0383DPA's higher power supply efficiency has two important benefits. It uses a small WPAK3 package that reduces the chip mounting area to about half that of a dual-package power MOSFET configuration, offering the same level of power supply efficiency. It also allows the device to deliver more output current. Smaller synchronous-rectification DC/DC converters are thus enabled, facilitating the higher mounting densities eagerly sought in mobile devices and other products in which small size adds convenience.
The high-side power MOSFET in the RJK0383DPA has a drain-gate load (Qgd) of 1.5nC (at VDD=10V) for a fast switching speed and correspondingly high efficiency. The device's low-side power MOSFET has a low on-resistance (RDS (on)) of 3.7mΩ (typical, at 4.5V) that reduces power loss. Additionally, the device integrates a Schottky barrier diode that is connected via low-inductance wiring to the low-side power MOSFET. This design speeds up the switching of current flow to the SBD during the DC/DC converter's dead time, for less power loss. It also suppresses voltage spikes during switching, reducing noise.
Availability: Fourth quarter of 2008.
Renesas Technology Corp., www.renesas.com