特点
Dynamically Adjustable Output from 0.3V to 3.5V
Very Low Quiescent Current: Only 20μA During Operation
600mA Output Current
Internal P-Channel MOSFET Bypass Transistor
High Efficiency: Up to 96%
1.5MHz Constant Frequency Operation
No Schottky Diode Required
Low Dropout Operation: 100% Duty Cycle
2.5V to 5V Input Voltage Range
Drives Optional External P-Channel MOSFET
Shutdown Mode Draws < 1μA Supply Current
Current Mode Operation for Excellent Line and Load Transient Response
Overtemperature Protected
Available in 8-Lead 3mm x 3mm DFN Package
典型应用
典型应用
描述
The LTC?3403 is a high efficiency monolithic synchronous buck regulator optimized for WCDMA power amplifier applications. The output voltage can be dynamically programmed from 0.3V to 3.5V. At V OUT > 3.6V an internal bypass P-channel MOSFET connects V OUT directly to V IN , eliminating power loss through the inductor. Selectable forced continuous mode enables fast V OUT response to the controlling input.
Supply current is only 20μA in Burst Mode? operation and drops to <1μA in shutdown. The 2.5V to 5V input voltage range makes the LTC3403 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems.
Switching frequency is internally set at 1.5MHz, 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.
The LTC3403 is available in a low profile 8-lead 3mm x 3mm DFN package.