LTC3410_15 Datasheet, PDF (1/16 Pages) Linear Technology – 2.25MHz, 300mA Synchronous Step-Down Regulator in SC70

LTC3410
2.25MHz, 300mA
Synchronous Step-Down
Regulator in SC70
FEATURES
■ _{High Efficiency: Up to 96%}
■ _{Low Ripple (20mVP-P) Burst Mode Operation: IQ 26µA}
■ _{Low Output Voltage Ripple}
■ _{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}
■ _{Wireless and DSL Modems}
■ _{Digital Cameras}
■ _{MP3 Players}
■ _{Portable Instruments}
DESCRIPTIO
The LTC^®3410 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 26µA, dropping to <1µA in shutdown.
The 2.5V to 5.5V input voltage range makes the LTC3410
ideally suited for single Li-Ion battery-powered applica-
tions. 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.
The LTC3410 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 LTC3410 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, 6580258, 6304066, 6127815, 6498466, 6611131, 5994885.
TYPICAL APPLICATIO
V_IN
2.7V
TO 5.5V
C_IN
4.7µF
CER
V_IN
SW
LTC3410
RUN
V_FB
GND
4.7µH
10pF
887k
412k
3410 TA01a
V_OUT
2.5V
C_OUT
4.7µF
CER
Efficiency and Power Loss
vs Output Current
100
1
90
80
70
EFFICIENCY
0.1
60
50
0.01
40
POWER LOSS
30
20
10
0
0.1
V_IN = 2.7V
V_IN = 3.6V
V_IN = 4.2V
0.001
0.0001
1
10
100
1000
OUTPUT CURRENT (mA)
3410 TA01b
3410fb
1