LTC3204-5_15 Datasheet, PDF (1/12 Pages) Linear Technology – Low Noise Regulated Charge Pump in 2 2 DFN

LTC3204-3.3/LTC3204-5/
LTC3204B-3.3/LTC3204B-5
Low Noise Regulated
Charge Pump in 2 × 2 DFN
FEATURES
■ _{Fixed 3.3V or 5V Outputs}
■ _{VIN Range:}
1.8V to 4.5V (LTC3204-3.3/LTC3204B-3.3)
2.7V to 5.5V (LTC3204-5/LTC3204B-5)
■ _{Output Current:}
Up to 150mA (LTC3204-5/LTC3204B-5)
Up to 50mA (LTC3204-3.3/LTC3204B-3.3)
■ _{Automatic Burst Mode}^® _{Operation with IQ = 48µA}
(LTC3204-3.3/LTC3204-5)
■ _{Constant Frequency Operation at All Loads}
(LTC3204B-3.3/LTC3204B-5)
■ _{Low Noise Constant Frequency (1.2MHz) Operation*}
■ _{Built-In Soft-Start Reduces Inrush Current}
■ _{Shutdown Disconnects Load from Input}
■ _{Shutdown Current <1µA}
■ _{Short-Circuit/Thermal Protection}
■ _{Available in Low Profile 6-Lead DFN Package}
U
APPLICATIO S
■ _{2 AA Cell to 3.3V}
■ _{Li-Ion to 5V}
■ _{USB On-The-Go Devices}
■ _{White LED Drivers}
■ _{Handheld Devices}
DESCRIPTIO
The LTC^®3204-3.3/LTC3204-5/LTC3204B-3.3/LTC3204B-5
are low noise, constant frequency (1.2MHz) switched ca-
pacitor voltage doublers. The LTC3204-3.3/LTC3204B-3.3
can produce a regulated output voltage of 3.3V
from a minimum input voltage of 1.8V (2 alkaline cells)
whereas the LTC3204-5/LTC3204B-5 can produce 5V from
a minimum of 2.7V (Li-Ion battery) input.
LTC3204-3.3/LTC3204-5 feature automatic Burst Mode^®
operation at light loads to maintain low supply current
whereas LTC3204B-3.3/LTC3204B-5 feature constant
frequency operation at any load. Built-in soft-start circuitry
prevents excessive inrush current during start-up. Thermal
shutdown and current-limit circuitry allow the parts to
survive a continuous short-circuit from V_OUT to GND.
High switching frequency minimizes overall solution
footprint by allowing the use of tiny ceramic capaci-
tors. In shutdown, the load is disconnected from the
input and the quiescent current is reduced to <1µA. The
LTC3204-3.3/LTC3204-5/LTC3204B-3.3/LTC3204B-5 are
available in a low profile (0.75mm) 6-lead 2mm × 2mm
DFN package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Burst Mode is a registered trademark of Linear Technology Corporation.
*Protected by U.S. Patents including 6411531.
TYPICAL APPLICATIO
2.2µF
2.7V TO 5.5V
2.2µF
5
2 ^C–
V_IN
4
C⁺
V_OUT
3
LTC3204-5/
LTC3204B-5
1, 7
GND
6
OFF ON
SHDN
5V
2.2µF
3204 TA01a
Output Ripple vs Load Current
30
OUTPUT CAPACITANCE = 2.2µF
V_IN = 3.6V
25
20
15
LTC3204-5
10
LTC3204B-5
5
0
0 25 50 75 100 125 150
OUTPUT CURRENT (mA)
3204 TA01b
3204fa
1