Features: 1.6V to 5.5V Input Voltage Range
Internal Soft-Start
Selectable 1.7MHz or 2.6MHz Constant FrequencyOperation
Internal Oscillator can be Synchronizable to anExternal Clock, 1MHz to 3MHz Range
High Efficiency: Up to 95%
Very Low Quiescent Current: Only 65µA DuringBurst Mode® Operation
600mA Output Current (VIN = 1.8V, VOUT = 1.2V)
750mA Peak Inductor Current
No Schottky Diode Required
Low Dropout Operation: 100% Duty Cycle
0.613V Reference Voltage
Stable with Ceramic Capacitors
Shutdown Mode Draws <1µA Supply Current
Current Mode Operation for Excellent Line and LoadTransient Response
Overtemperature Protection
Available in a Low Profile (0.75mm) 8-Lead(3mm * 3mm) DFN PackageApplication Cellular Phones
Digital Cameras
MP3 PlayersSpecificationsInput Supply Voltage .................................. 0.3V to 6V
RUN, VFB, MODE, SYNC Voltages . 0.3V to (VIN + 0.3V)
SW Voltage ................................... 0.3V to (VIN + 0.3V)
Operating Temperature Range (Note 2) .. 40°C to 85°C
Junction Temperature (Note 3) ............................ 125°C
Storage Temperature Range ................ 65°C to 125°C
DescriptionThe LTC®3409 is a high efficiency, monolithic synchronous buck regulator using a constant frequency, current mode architecture. The output voltage is adjusted via an external resistor divider. Fixed switching frequencies of 1.7MHz and 2.6MHz are supported. Alternatively, an internal PLL will synchronize to an external clock in the frequency range of 1MHz to 3MHz. This range of switching frequencies allows the use of small surface mount inductors and capacitors, including ceramics.
Supply current during Burst Mode operation is only 65µA dropping to <1µA in shutdown. The 1.6V to 5.5V input voltage range makes the LTC3409 ideally suited for single cell Li-Ion, Li-Metal and 2-cell alkaline, NiCd or NiMH battery-powered applications. 100% duty cycle capability provides low dropout operation, extending battery life in portable systems. Burst Mode operation can be userenabled,increasing efficiency at light loads, further extending battery life.
LTC3409 Data Sheet
