LTC3448

The LTC®3448 is a high efficiency, monolithic, synchronous buck regulator using a constant frequency, current mode architecture. Supply current during operation is only 32A  (linear regulator mode) and drops to <1A in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3448 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. At moderate output load levels, PWM pulse skipping mode operation provides very low output ripple voltage for noise sensitive applications.

The LTC3448 automatically switches into linear regulator operation at very low load currents to maintain <5mV _P-P output voltage ripple. Supply current in this mode is  typically 32A. The switch to linear regulator mode occurs at a threshold of 3mA. Linear regulator operation can be set to on, off or automatic turn on/off.

Switching frequency is selectable at either 1.5MHz or 2.25MHz, allowing the use of small surface mount inductors and capacitors.

The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage. The LTC3448 is available in a low profile 3mm * 3mm DFN package or thermally enhanced 8-lead MSOP.