Sipex Corporation, designer and manufacturer of high-performance analog semiconductors for the battery-powered, portable electronics market, announced the immediate availability of its new SP6650 low voltage DC/DC buck regulator. The SP6650 uses a proprietary PFM (pulse frequency modulation) control architecture to deliver very high efficiencies (up to 95%) over an extremely wide output current range (50mA to 500mA), an important feature in portable devices where output current fluctuates widely depending on system load demands. The control loop operates between continuous and discontinuous current modes, combining the inherent light load efficiency of PFM control with the high current delivery normally associated with PWM control. The SP6650 provides a complete power solution with its on board power MOSFET, and an external inductor and several additional discrete capacitors and resistors. The SP6650 sources up to 500mA with a 2% accuracy at either its fixed 3.3V output, or at a user programmable output voltage between 2.8V and 6.5V. The programmable peak inductor current feature gives designers the flexibility to select the external inductor based on cost, performance and size. Quiescent current and shutdown current are very low at 70uA and 0.3nA respectively and an output ripple of as low as 10mV is possible.

"While there are many buck regulators for portable devices available in the market today, the SP6650 stands out with its unique combination of high efficiency and low quiescent current over such a wide output current range," said Todd Sherman, Manager of Sipexýs Power Management Product Line. "Many portable device designers choose the SP6650 because it maximizes battery life over a variety of load conditions commonly found in lithium ion and 3 to 4 cell alkaline battery powered devices".

About the SP6650

Sipex has once again come out with a very usable regulator at an extremely attractive price. Until last year I only ever thought of the company in terms of its backlighting technology for watches -- now it has become a serious contender in some power management areas.

The SP6650 takes a 2.7 to 6.5 V input to a fixed 3.3-V output, or one that can be adjusted from 1.25 to 5.0 V with a potential divider on the feedback pin -- that of course drives a comparator on-chip with the on-board reference driving the other side. The 500mA capability is without any external switch being needed and Sipex uses its inductor peak current control system. There is also a low battery indicator, a dedicated manual shutdown pin and an over-temperature protector. The power efficiency numbers are impressive. There is no indication that I could find on the data sheet of the operating frequency which can be important to designers working in arenas where there are potential EMC problems.