LM3224 Datasheet, PDF (1/18 Pages) National Semiconductor (TI) – 615kHz/1.25MHz Step-up PWM DC/DC Converter

December 2004
LM3224
615kHz/1.25MHz Step-up PWM DC/DC Converter
General Description
The LM3224 is a step-up DC/DC converter with a 0.15Ω
(typ.), 2.45A (typ.) internal switch and pin selectable operat-
ing frequency. With the ability to convert 3.3V to multiple
outputs of 8V, -8V, and 23V, the LM3224 is an ideal part for
biasing TFT displays. With the high current switch it is also
ideal for driving high current white LEDs for flash applica-
tions. The LM3224 can be operated at switching frequencies
of 615kHz and 1.25MHz allowing for easy filtering and low
noise. An external compensation pin gives the user flexibility
in setting frequency compensation, which makes possible
the use of small, low ESR ceramic capacitors at the output.
An external soft-start pin allows the user to control the
amount of inrush current during start up. The LM3224 is
available in a low profile 8-lead MSOP package.
Features
n Operating voltage range of 2.7V to 7V
n 615kHz/1.25MHz pin selectable frequency operation
n Over temperature protection
n Optional soft-start function
n 8-Lead MSOP package
Applications
n TFT Bias Supplies
n Handheld Devices
n Portable Applications
n GSM/CDMA Phones
n Digital Cameras
n White LED Flash/Torch Applications
Typical Application Circuit
© 2004 National Semiconductor Corporation DS200976
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