PT4305
1x/1.5x Auto-Adjust Charge Pump One Channel White LED
Driver for Flash
FEATURES
1x/1.5x auto-adjust charge pump
350mA maximum load current
<10% feedback voltage reference error
Dimming LED by PWM signal through
EN/PWM pin
Less than 1uA shutdown current
Built-in soft-start and soft mode decision
Less than 1uA shutdown current r
Thermal shutdown n
Shorted LED protection
GENERAL DESCRIPTION
PT4305 is a 1x/1.5x auto-adjust charge pump
white LED driver with maximum 350mA load.
Auto-adjust
charge
pump
achieves
high
efficiency for Li-Ion battery supply. Few external
components (two flying capacitors, two filter
capacitors at VIN and VOUT, and one feedback
resistor) make PT4305 ideally suited for mobility
application.
The current through the LED can be pre-set by
feedback resistor. And the LED can also be
dimmed by PWM control signal. Built-in soft-start
circuit prevents the inrush current from supply
source during power on and 1x/1.5x mode
change. Thermal shutdown and current limiter
prevent
PT4305
being
damaged
by
the
high-level current through it. Shutdown current
less than 1uA makes the battery time longer.
PT4305 is packaged with QFN-10, MSOP-10
and SOP-14, and it is also available with different
feedback voltage references: 315mV, 236mV,
157mV, and 78mV.
APPLICATION
Cell Phones
Camera Flash Driver
Small LCD Displays
1 Watt White LED Driver
Handheld Computers and PDAs
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