The LTC1707 is a high efficiency monolithic current mode synchronous buck regulator using a fixed frequency architecture. The operating supply range is from 8.5V down to 2.85V, making it suitable for both single and dual lithium-ion battery-powered applications. Burst Mode operation provides high efficiency at low load currents. 100% duty cycle provides low dropout operation, extending operating time in battery-powered systems. The switching frequency is internally set at 350kHz, allowing the use of small surface mount inductors. For noise sensitive applications it can be externally synchronized up to 550kHz. Burst Mode operation is inhibited during synchronization or when the SYNC/MODE pin is pulled low preventing low frequency ripple from interfering with audio circuitry. Soft-start is provided by an external capacitor.