Power-controller IC pumps low voltage and high current
( 01 Aug 2004 )
by Bill Schweber
With the MIC2168 and MIC2169 dc/dc synchronous buck controllers from Micrel, you can develop a supply which delivers up to 20A at voltages as low as 0.8V. The fixed-frequency 1MHz pulse-width modulation (PWM) design of the MIC2168 allows you to use small passive components. In contrast, the 500kHz MIC2169 is more efficient for driving large MOSFETS with their inherent large gate charge. Both devices can achieve efficiency in the 95% range, due to an adaptive gate-drive technique that reduces shoot-through current. High-side current sensing for the MOSFETs eliminates the need for a costly current-sense resistor. Also on the output side, the ICs offer overvoltage protection, current limiting, and short-circuit protection, to protect both the IC and the load it is supporting. The MSOP-10 devices are priced at $1.92 (MIC2168) and $1.74 (MIC2169) in 1000-piece lots.
