The LTC 3564 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. Supply current during operation is only 20A, dropping to 1A in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3564 ideally suited for single Li-Ion battery-powered or 3.3V to 5V input voltage applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. Automatic Burst Mode operation increases efficiency at light loads, further extending battery runtime.