Micrel Launches New 30A Synchronous Buck Controller For PoL DC-DC Applications
Micrel Inc. launched the MIC2159, a synchronous buck controller featuring high efficiency, less components, small size and thermal capability point-of-load (PoL) dc-dc conversion. The IC is targeted at networking, telecom/datacom, server, graphic card, and storage applications.
"The MIC2159 addresses our customer's need for simple, cost-effective, small and thermal-capable high current solutions for their point-of-load dc-dc applications," satated Ralf Muenster, Micrel's Marketing Director for Power Products. "The MIC2159 has a typical minimum on-time of 30ns, which is significantly lower than the competition. It allows very low PWM duty ratio required by datacom applications that need to convert 12 to 1V in a single step, increasing the overall efficiency by eliminating intermediate voltage rails and reducing the system cost."
The MIC2159 operates from a wide 3 to 14.5V input voltage range, thereby allowing the device to deploy step down voltages for systems using 3.3V, 5V, and 12V power busses. With a programmable minimum output voltage of 0.8V, the MIC2159 can power the latest generation CPUs, DSPs, FPGAs, and ASICs. Powerful internal gate drivers allow the device to power external MOSFETs that can provide up to 30A of output current. The MIC2159 operates at 400 KHz, allowing the smallest possible external components and highest level of efficiency, especially in high output current applications. With a proprietary adaptive gate drive technique that reduces MOSFET shoot-through current, the MIC2159 is capable of efficiencies of greater than 95%. Significant cost savings are achieved by eliminating the need for an expensive current sensing resistor by instead sensing current through the high-side N-Channel MOSFET. Current limit accuracy is maintained by a positive temperature coefficient that tracks the increasing on-resistance of the external MOSFET. Additionally, with the built-in soft-start, the MIC2159 reduces in-rush current while eliminating the need for an external soft-start capacitor.
The MIC2159 is offered in a low-pin count, small and thermally capable ePAD MSOP-10 package. This package option reduces design complexity and external components, and its small size and high thermal capability saves valuable board space when compared to bigger SOP-packaged solutions and allows the device to operate at high ambient temperatures at the same time. The device can also operate from -40 to 125°C junction temperature. The MIC2159 is released to volume production and priced at $1.69 in 1,000-piece quantities.
