Siliconix Announces the Si9172 Buck Converter IC

Siliconix Inc. (Santa Clara, CA), an 80.4-percent-owned subsidiary of Vishay Intertechnology Inc. (Malvern, PA), announced a new buck converter IC that features pulse-skipping modes (PSM) and bypass modes. The new Si9172 is suitable for use in cellular and cordless phones, notebook computers, and PDAs.

The Si9172 has an input-voltage range of 2.7V to 6V and a dynamic adjustable output of 1.5V to 3.6V. When operating in PSM mode, it converts power with greater than 90 percent efficiency at a 170mA load. In bypass mode, the Si9172 delivers 800mA with a typical 95 percent efficiency.

The Si9172 requires low quiescent currents of 220uA in PSM mode and 110uA in bypass mode, with a shutdown current of 1uA. In the PSM mode, the output-voltage regulation can be adjusted by an external analog-voltage signal. An on-board MOSFET simplifies converter designs by reducing the component count. Integrated protection features include undervoltage lockout, power-on reset, soft-start and over-temperature protection.

Packaged in the MSOP-10, samples and product quantities of the Si9172 are currently available, with lead times of eight weeks for larger orders. Pricing in 50,000-unit quantities is $1.15.