Demonstration circuit 432 is a step-down converter, featuring either the LTC1875 or LTC1879 high frequency monolithic switching regulators. With an input voltage range from 2.65V to 6V, the LTC1875 is ideal for Li-Ion applications, such as PDAs, cellular phones, and digital cameras. For applications with higher input voltages, the LTC1879 is the choice with its maximum input voltage limit of 10V. Both devices have switch current limits over 1A (LTC1875-1.6A, LTC1879-1.8A), which allows these ICs to deliver high(er) power to small, low-profile applications. While the standard operating frequency of both parts is 550 kHz, the switching can be externally set as high as 750 kHz. All these features make the LTC1879 (DC432A) or LTC1875 (DC432B) perfectly suited for battery- powered, surface mount applications.