2.25MHz, 800mA Synchronous Step-Down Regulator in ThinSOT

The LTC3560 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. Supply current during operation is only 16µA, dropping to <1µA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3560 ideally suited for single Li-Ion/Li-Polymer battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems.

Switching frequency is internally set at 2.25MHz, allowing the use of small surface mount inductors and capacitors. For noise sensitive applications the LTC3560 can be externally synchronized from 1MHz to 3MHz. Burst Mode operation is inhibited during synchronization or when the SYNC/MODE pin is pulled high, preventing low frequency ripple from interfering with audio circuitry.

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 LTC3560 is available in a low profile (1mm) ThinSOT package.

Applications

* Cellular Telephones

* Wireless and DSL Modems

* Digital Still Cameras

* Media Players

* Portable Instruments

* High Efficiency: Up to 95%

* Low Output Ripple (<20mVP-P): Burst Mode® Operation: IQ = 16µA

* 2.5V to 5.5V Input Voltage Range

* 2.25MHz Constant Frequency Operation

* Synchronizable to External Clock

* No Schottky Diode Required

* Stable with Ceramic Capacitors

* Low Dropout Operation: 100% Duty Cycle

* 0.6V Reference Allows Low Output Voltages

* Shutdown Mode Draws < 1µA Supply Current

* ±2% Output Voltage Accuracy

* Current Mode Operation for Excellent Line and Load Transient Response

* Overtemperature Protected

* Low Profile (1mm) ThinSOT™ Package