Features

• High Efficiency: Up to 96%
• Very Low Quiescent Current: Only 20μA
• 1.25A Output Current
• 2.5V to 5.5V Input Voltage Range
• 2.25MHz Constant Frequency Operation
• No Schottky Diode Required
• Low Dropout Operation: 100% Duty Cycle
• 0.6V Reference Allows Low Output Voltages
• Shutdown Mode Draws ≤ 1μA Supply Current
• Current Mode Operation for Excellent Line and
• Load Transient Response
• Overtemperature Protected
• Low Profile (1mm) ThinSOT and 6-Lead (2mm × 3mm) DFN Packages

Typical Application

Description

The LTC3564 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. Supply current during operation is only 20μA, dropping to ≤1μA 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 drop- out operation, extending battery life in portable systems. Automatic Burst Mode operation increases efficiency at light loads, further extending battery runtime.

Switching frequency is internally set at 2.25MHz, allowing the use of small surface mount inductors and capacitors.

The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage. The LTC3564 is available in low profile (1mm) ThinSOT and 6-Lead (2mm × 3mm) DFN packages.