LTC3201_15 Datasheet, PDF (1/8 Pages) Linear Technology – 100mA Ultralow Noise Charge Pump LED Supply with Output Current Adjust

FEATURES
s _{Input Noise Filter Minimizes Supply Noise}
s _{Constant Frequency Operation}
s _{3-Bit LED Current Control}
s _{No Inductors}
s _{Low Shutdown Current: IIN < 1µA}
s _{Output Current: 100mA}
s _{VIN Range: 2.7V to 4.5V}
s _{1.8MHz Switching Frequency}
s _{Soft-Start Limits Inrush Current at Turn-On}
s _{Short-Circuit and Overtemperature Protected}
s _{Available in 10-Pin MSOP Package}
U
APPLICATIO S
s _{White LED Backlighting}
s _{Programmable Boost Current Source}
, LTC and LT are registered trademarks of Linear Technology Corporation.
LTC3201
100mA Ultralow Noise
Charge Pump LED Supply
with Output Current Adjust
DESCRIPTIO
The LTC^®3201 is an ultralow noise, constant frequency,
charge pump DC/DC converter specifically designed for
powering white LEDs. The part produces a low noise
boosted supply capable of supplying 100mA of output
current. LED current is regulated for accurate and stable
backlighting. A 3-bit DAC provides output current adjust
for brightness control.
Low external parts count (one small flying capacitor and
three small bypass capacitors) and small MSOP-10 pack-
age size make the LTC3201 ideally suited for space con-
strained applications. An input noise filter further reduces
input noise, thus enabling direct connection to the battery.
High switching frequency enables the use of small external
capacitors.
The LTC3201 contains overtemperature protection and
can survive an indefinite output short to GND. Internal
soft-start circuitry also prevents excessive inrush current
on start-up. A low current shutdown feature disconnects
the load from V_IN and reduces quiescent current to less
than 1µA.
TYPICAL APPLICATIO
Ultralow Noise White LED Driver
with Adjustable Current Control
0.22µF
Input Current Ripple
I_OUT = 100mA
I_IN = 205mA
V_IN = 3.6V
+
Li ION
1µF
LED
CURRENT
ADJUST
0.22µF
3
CM
CP
V_IN
FILTER
V_OUT
LTC3201
D0-D2
GND
FB
UP TO
6-WHITE LEDs
1µF
•••
50mA/DIV
56Ω 56Ω
56Ω
3201 TA01a
100ns/DIV
3201 TA01b
3201f
1