LTC3406B-2

Features:

High Efficiency: Up to 96%
600mA Output Current at V(IN)  = 3V
2.5V to 5.5V Input Voltage Range
2.25MHz Constant Frequency Operation
No Schottky Diode Required
Low Dropout Operation: 100% Duty Cycle
Low Quiescent Current: 350A
0.6V Reference Allows Low Output Voltages
Shutdown Mode Draws <1A Supply Current
Current Mode Operation for Excellent Line and Load Transient Response
Overtemperature Protected
Low Profile (1mm) SOT-23 Package


Application

Cellular Telephones
Personal Information Appliances
Wireless and DSL Modems
Digital Still Cameras
MP3 Players
Portable Instruments


Specifications

Input Supply Voltage .................................. 0.3V to 6V
RUN, V(FB)  Voltages..................................... 0.3V to V(IN)
SW Voltage (DC) ......................... 0.3V to (V[IN]  + 0.3V)
P-Channel Switch Source Current (DC).............  800mA
N-Channel Switch Sink Current (DC).................  800mA
Peak SW Sink and Source Current ........................  1.3A
Operating Temperature Range (Note 2).. 40°C to 85°C
Maximum Junction Temperature (Notes 3, 6)..... 125°C
Storage Temperature Range................  65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C


Description

The LTC(R) 3406B-2 is a high efficiency monolithic synchro-nous buck regulator using a constant frequency, current
mode architecture. Supply current with no load is 350A,dropping to <1A in shutdown. The 2.5V to 5.5V input
voltage range makes the LTC3406B-2 ideally suited for single Li-Ion battery-powered applications. 100% duty
cycle capability provides low dropout operation, extend-ing battery life in portable systems. PWM pulse skipping
mode operation provides very low output ripple voltage fornoise sensitive applications.
The switching frequency is internally set at 2.25MHz, allow-ing the use of tiny 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 LTC3406B-2 is available in a low pro-file (1mm) SOT-23 package. Refer to LTC3406 for appli-(R)cations that require Burst Mode  operation.