LTC3410B_15 Datasheet, PDF (1/16 Pages) Linear Technology – 2.25MHz, 300mA Synchronous Step-Down Regulator in SC70

FEATURES
■ _{High Efficiency: Up to 96%}
■ _{300mA Output Current at VIN = 3V}
■ _{380mA Minimum Peak Switch Current}
■ _{2.5V to 5.5V Input Voltage Range}
■ _{2.25MHz Constant Frequency Operation}
■ _{No Schottky Diode Required}
■ _{Low Dropout Operation: 100% Duty Cycle}
■ _{Stable with Ceramic Capacitors}
■ _{0.8V 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}
■ _{Available in Low Profile SC70 Package}
U
APPLICATIO S
■ _{Cellular Telephones}
■ _{Personal Information Appliances}
■ _{Wireless and DSL Modems}
■ _{Digital Still Cameras}
■ _{MP3 Players}
■ _{Portable Instruments}
LTC3410B
2.25MHz, 300mA
Synchronous Step-Down
Regulator in SC70
DESCRIPTIO
The LTC^®3410B is a high efficiency monolithic synchro-
nous buck regulator using a constant frequency, current
mode architecture. The device is available in adjustable
and fixed output voltage versions. Supply current during
operation is only 200µA, dropping to <1µA in shutdown.
The 2.5V to 5.5V input voltage range makes the LTC3410B
ideally suited for single Li-Ion battery-powered applica-
tions. 100% duty cycle provides low dropout operation,
extending battery life in portable systems. PWM pulse
skipping mode operation 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 LTC3410B is specifically designed to work well with
ceramic output capacitors, achieving very low output
voltage ripple and a small PCB footprint.
The internal synchronous switch increases efficiency and
eliminates the need for an external Schottky diode. Low
output voltages are easily supported with the 0.8V feed-
back reference voltage. The LTC3410B is available in a
tiny, low profile SC70 package.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All
other trademarks are the property of their respective owners. Protected by U.S. Patents,
including 5481178, 5994885, 6580258, 6304066, 6127815, 6498466, 6611131.
TYPICAL APPLICATIO
V_IN
2.7V
TO 5.5V
C_IN
2.2µF
CER
V_IN
SW
LTC3410B
RUN
V_FB
GND
4.7µH
10pF
232k
464k
3410 TA01
V_OUT
1.2V
C_OUT
2.2µF
CER
100
90
80
70
60
50
40
30
20
20
0
1
Efficiency and Power Loss
vs Output Current
1
EFFICIENCY
0.1
0.01
POWER LOSS
0.001
V_IN = 2.7V
V_IN = 3.6V
V_IN = 4.2V _0.0001
10
100
1000
OUTPUT CURRENT (mA)
3410 TA01b
3410bfa
1