LTC3547

The LTC®3547 is a dual, 2.25MHz, constant-frequency, synchronous step-down DC/DC converter in a tiny 3mm × 2mm DFN package. 100% duty cycle provides low dropout operation, extending battery life in portable systems. Low output voltages are supported with the 0.6V feedback reference voltage. Each regulator can supply 300mA continuous output current.

The input voltage range of LTC3547 is 2.5V to 5.5V, making it ideal for Li-Ion and USB powered applications. Supply current during operation is only 40µA and drops to < 1µA in shutdown. Automatic Burst Mode® operation increases effi ciency at light loads, further extending battery life. An internally set 2.25MHz switching frequency allows the use of tiny surface mount inductors and capacitors. Internal soft-start reduces inrush current during startup.

All outputs are internally compensated to work with ceramic capacitors. The LTC3547 is available in a low profi le (0.75mm) 3mm × 2mm DFN package. The LTC3547 is also available in a fi xed output voltage confi guration, eliminating the need for the external feedback networks (see Table 2).