Buck regulator-with-LDO boosts portable power

Milpitas, Calif. – Linear Technology’s LTC3448 low-noise, synchronous buck regulator can deliver up to 600 mA at very high efficiency over a wide load for handheld wireless applications using single cell lithium-ion, multi-cell alkaline, and NiMH sources. When output current is greater than 3 mA, the regulator switches at a user-selectable frequency of 1.5 or 2.25 MHz. If output current drops to 3 mA or below, the chip automatically shifts to its low-dropout (linear) regulator.