Dual-Type Power MOSFET Delivers Higher Power Supply Efficiency in DC/DC Converters for Products Such as Laptop PCs and Communication Devices
(Product News, 12 Aug 2008 )
Renesas Technology has announced the RJK0383DPA dual-type power MOSFET for synchronous rectification DC/DC converters for memory or ASICs in products such as laptop PCs and communication devices. It achieves higher power supply efficiency. Sample shipments will begin in October 2008 in Japan.
RJK0383DPA incorporates dual power MOSFETs of two different types, composing a synchronous rectification DC/DC converter in a WPAK*1 (Renesas Technology package code) high-thermal-radiation package measuring 5.1 × 6.1 mm and 0.8 mm thick (max.) The features of the RJK0383DPA are summarized below. (1) Advance process delivering outstanding power supply efficiency of 91.6% The RJK0383DPA achieves higher power supply efficiency by using state-of-the-art 10th-generation power MOSFETs. For example, power supply efficiency when converting 12 V input to 1.1 V output is 91.6% (at 600 kHz switching frequency), the best in the industry. Power supply output current that power MOSFETs handle increases double from earlier dual-type products from Renesas Technology. (2) Enables more compact power supply design and higher mounting density through reduction of chip mounting area to half that of earlier dual-package power MOSFET configurations By achieving higher power supply efficiency, the RJK0383DPA reduces the chip mounting area to about half that of a dual-package power MOSFET configuration, enabling a more compact synchronous rectification DC/DC converter and higher mounting density. The RJK0383DPA will be particularly effective for applications requiring compactness, such as mobile devices. The RJK0383DPA will be followed by two additional products having different output current ratings, the RJK0384DPA and RJK0389DPA. Sample shipments of these will also begin in October 2008 in Japan.
The RJK0383DPA integrates dual power MOSFETs of two different types, one as the high-side element and the other as the low-side element.*2 The high-side power MOSFET has a drain-gate load (Qgd) of 1.5 nC (at VDD=10V) to provide high switching speed and correspondingly high efficiency. The low-side power MOSFET has a low on-resistance*3 (RDS (on)) of 3.7 mW (typ. : at 4.5 V) to reduce power loss. In addition, the low-side power MOSFET is integrated on the same chip as the schottky barrier diode (SBD) to minimize the wiring inductance*4 between them. This speeds up the switch of current flow to the Schottky barrier diode during the DC/DC converter’s dead time, further reducing loss. It also has the effect of suppressing voltage spikes during switching, thereby reducing noise. The 10th-generation process used to fabricate the RJK0383DPA achieves lower loss and higher efficiency than the 9th-generation process that preceded it. On-resistance is about 30% lower while the opposing characteristics of gate charge capacitance (Qg) and drain-gate load (Qgd) are approximately 27% and 30% lower, respectively (both in comparison with earlier power MOSFET products having the same on-resistance).
