Vishay Intertechnology released two synchronous buck step-down controller ICs designed to operate with external MOSFETs in dc-to-dc converter circuits that require output currents upwards of 10 A. The high-voltage SiP12201 and low-voltage SiP12202 controllers both are designed to enable flexible, efficient voltage conversion in a broad range of applications in battery-powered, telecom, and industrial end systems. The devices' synchronous buck architecture allows voltages to be converted with efficiencies of 93%, prolonging battery life while lowering heat in enclosed field-mounted or rack-mounted systems and reducing the need for cooling systems.
The input voltage range is 4.2 to 26 V for the SiP12201 and 2.7 to 5.5 V for the SiP12202. Adjustable output voltages for the two devices range from 0.6 to 20 V for the SiP12201 and from 0.6 to 5.5 V for the SiP12202. The ability to reach 0.6 V at the low end is a unique capability for a device with a 500-kHz operating frequency and ensures the SiP12201 and SiP12202 will be able to satisfy the future requirements of lower voltages.
The SiP12201 synchronous buck step-down controller is designed for industrial controls, wireless and cable modems, set-top boxes, LCD TVs, telecom power supplies and servers, point-of-load (POL) modules, and for delivering regulated power to microprocessors, ASICs, FPGAs, and DSPs. Able to drive n-channel MOSFETs for both the high side and low side in a synchronous converter, the SiP12201 helps to reduce overall design costs by allowing the use of two lower-cost n-channel devices instead of one n-channel and one p-channel device. The SiP12201 also offers the advantage of 500-kHz operation, which allows the use of smaller passive components in converter designs.
The SiP12202 drives an n-channel MOSFET on the low side and a p-channel MOSFET on the high side. Use of the p-channel MOSFET on the high side eliminates the need for an external charge pump while also simplifying the high-side gate driver. Operation up to 500 kHz enables use of smaller passive components for more compact end systems.
Both of the new step-down controllers include a combination compensation/shutdown pin, as well as additional protection features such as under-voltage lockout, power good output, output-current limit, and thermal shutdown. Internal soft start prevents voltage spikes during startup. Each controller is available in a lead-free MLP33-10 package and is specified to operate over a temperature range of -40 to +85°C.
Samples and production quantities of the new synchronous buck step-down controller ICs are available now, with lead times of six to seven weeks for larger orders. Pricing in 1000-piece quantities is $0.82 for the SiP12201 and $0.80 for the SiP12202. Vishay can be found on the Internet at www.vishay.com.