More board room with SSS buck power converter

24th September 2007

ES Admin

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Demands for increased power requirements in a limited space, especially in datacom and server designs, have been addressed by the new SC4612 28-volt synchronous buck power converter from Solid State Supplies to enable system designers to increase port density while reducing board size.

With a wide input range and a programmable 1.2 MHz frequency for compact power supply designs, the SC4612’s synchronous rectified buck topology results in 95% peak efficiency that provides compact on-board dc to dc converter designs with 93W/sq. inch of power density

The SC4612 is a voltage-mode synchronous, PWM controller that operates in a 4.5V to 28V input voltage range and drives external N-channel MOSFETs. The design uses a novel low-voltage technique that enables high-frequency switching with high gate drive. The output voltage can be as low as 0.5V.

Running at a constant 1.2MHz frequency that can be programmed using an external capacitor, the device’s 1.7A gate drive current is capable of driving large MOSFETs, resulting in efficient 40A single phase converter designs.

The device supports an asynchronous start-up mode to keep the lower side MOSFET turned off until output is within regulation so that the external bus is not discharged. This is an ideal feature for applications with preset external voltage or pre-biased output voltage. Built-in cross conduction prevention circuitry prevents shoot-through, minimizing dead time and losses.

SC4612 features programmable current limit with built-in hiccup mode and over temperature protection. It is available in either an MLPD-12 or a SOIC-14 package in lead-free versions that meet RoHS/WEEE specifications and has a -40 to +125°C junction operating temperature range