LTC3406AB-2_15 Datasheet, PDF (1/16 Pages) Linear Technology – 2.25MHz, 600mA Synchronous Step-Down Regulator in ThinSOT

FEATURES
■ _{High Efficiency: Up to 96%}
■ _{600mA 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}
■ _{±2% Output Voltage Accuracy}
■ _{Low Quiescent Current: 200µA}
■ _{0.6V Reference Allows Low Output Voltages}
■ _{Shutdown Mode Draws <1µA Supply Current}
■ _{Internal Soft-Start Limits Inrush Current}
■ _{Current Mode Operation for Excellent Line and}
Load Transient Response
■ _{Overtemperature Protected}
■ _{Low Profile (1mm) ThinSOT}^TM _Package
APPLICATIONS
■ _{Cellular Telephones}
■ _{Personal Navigation Devices}
■ _{Wireless and DSL Modems}
■ _{Digital Still Cameras}
■ _{Media Players}
■ _{Portable Instruments}
LTC3406AB-2
2.25MHz, 600mA
Synchronous Step-Down
Regulator in ThinSOT
DESCRIPTION
The LTC^®3406AB-2 is a high efficiency monolithic synchro-
nous buck regulator using a constant frequency, current
mode architecture. Supply current with no load is 200μA
and drops to <1μA in shutdown. The 2.5V to 5.5V input
voltage range makes the LTC3406AB-2 ideally suited for
single Li-Ion battery-powered applications. 100% duty
cycle provides low dropout operation, extending battery
life in portable systems. PWM pulse skipping mode op-
eration provides very low output ripple voltage for noise
sensitive applications.
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 LTC3406AB-2 is available in a low
profile (1mm) ThinSOT package. Refer to LTC3406A for
applications that require Burst Mode^® operation.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
Burst Mode is a registered trademark of Linear Technology Corporation.
ThinSOT is a registered trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 5481178, 6580258.
TYPICAL APPLICATION
2.2μH*
V_IN
C_IN^†
V_IN
SW
4.7μF
CER
LTC3406AB-2
22pF
V_OUT
1.8V
600mA
C_OUT**
10μF
CER
RUN V_FB
GND
619k
309k
* MURATA LQH32CN2R2M33
** TAIYO YUDEN JMK316BJ106I
3406AB2 TA01a ^† TAIYO YUDEN JMK212BJ475
Efficiency vs Output Current
100
V_OUT = 1.8V
90
80
70
60
50
40
30
20
10
0
0.1
V_IN = 2.7V
V_IN = 3.6V
V_IN = 4.2V
1
10
100
OUTPUT CURRENT (mA)
1000
3406AB2 TA01b
3406ab2f
1