The LTC®3548-2 is a dual, constant frequency, synchronous step down DC/DC converter. Intended for low power applications, it operates from 2.5V to 5.5V input voltage range and has a constant 2.25MHz switching frequency, allowing the use of tiny, low cost capacitors and inductors with a profile ≤1.2mm. For channel 1, the output voltage is fixed at 1.8V/800mA; for channel 2, the output voltage is adjustable from 0.6V to VIN. Internal synchronous 0.35O, 1.2A/0.7A power switches provide high efficiency without the need for external Schottky diodes. A user selectable mode input is provided to allow the user to trade-off noise ripple for low power efficiency. Burst Mode® operation provides high efficiency at light loads, while Pulse Skip Mode provides low noise ripple at light loads. To further maximize battery run time, the P-channel MOSFETs are turned on continuously in dropout (100% duty cycle), and both channels draw a total quiescent current of only 40ΜA. In shutdown, the device draws <1ΜA.
