LTC3203_15 Datasheet, PDF (1/16 Pages) Linear Technology – 500mA Output Current Low Noise Dual Mode Step-Up Charge Pumps

FEATURES
■ _{Selectable Dual Mode Operation: 1:1.5 or 1:2}
■ _{High Output Current: Up to 500mA}
■ _{Low Noise Constant Frequency (1MHz/0.9MHz)}
Operation*
■ _{VIN Range: 2.7V to 5.5V}
■ _{Adjustable Output Voltage (LTC3203/LTC3203B)}
■ _{User Selectable Fixed Output Voltages: 4.5V or 5V}
(LTC3203-1 and LTC3203B-1)
■ _{Burst Mode}^® _{Operation with}
I_Q ~ 120µA (LTC3203/LTC3203-1)
■ _{Constant Freqency Operation at All Loads}
(LTC3203B/LTC3203B-1)
■ _{Soft-Start Limits Inrush Current at Turn-On}
■ _{Short-Circuit/Thermal Protection}
■ _{Shutdown Disconnects Load from Input}
■ _{Shutdown Current: < 1µA}
■ _{Available in a 10-pin (3mm × 3mm) DFN Package}
U
APPLICATIO S
■ _{High Current LED Backlight Supply for}
Cellphones/PDAs
■ _{Cellphone Camera Light Supply}
■ _{General Purpose 3.3V or Li-Ion to 5V Supply}
■ _{USB ON THE GO(OTG) Devices}
LTC3203/LTC3203-1
LTC3203B/LTC3203B-1
500mA Output Current
Low Noise Dual Mode
Step-Up Charge Pumps
DESCRIPTIO
The LTC^®3203/LTC3203-1/LTC3203B/LTC3203B-1 are low
noise, high efficiency charge pump DC/DC converters
capable of driving loads up to 500mA from a 2.7V to 5.5V
input. Low external parts count (two flying capacitors and
bypass capacitors at V_IN and V_OUT) make the LTC3203
family ideally suited for small, battery-powered applica-
tions.
Built-in soft-start circuitry prevents excessive inrush
current during start-up. High switching frequency enables
the use of small external capacitors. The LTC3203/
LTC3203-1 feature Burst Mode operation at light load to
achieve high efficiency whereas the LTC3203B/
LTC3203B-1 operate at constant frequency to achieve
lowest noise operation.
The LTC3203-1/LTC3203B-1 have a user selectable fixed
output voltage of 4.5V or 5V to power LEDs or logic
circuits. The FB pin of the LTC3203/LTC3203B can be used
to program the desired output voltage. The parts are short-
circuit and overtemperature protected and are available in
a low profile (3mm × 3mm) DFN package.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
Burst Mode is a registered trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
*Protected by U.S. Patents including 6411531.
TYPICAL APPLICATIO
V_IN
2.2µF
ON/OFF
R1*
100k
2.2µF
SHDN VSEL
LTC3203-1
V_IN
V_OUT
C1+
C2+
C1–
C2–
MODE GND
I_OUT(MAX)
300mA
300mA
500mA
500mA
V_SEL
LOW
HIGH
LOW
HIGH
V_OUT
4.5V
5V
4.5V
5V
*R1
316k
357k
357k
402k
OUTPUT PROGRAMMING
2.2µF
V_OUT
500mA
10µF
3203 F02
Efficiency vs V_IN at 300mA Load Current
100
90
80
V_OUT = 5V
70
V_OUT = 4.5V
60
50
40
30
20
10
0
2.5 3 3.5 4 4.5 5 5.5
V_IN (V)
3203 G05
32031fa
1