LM3211 Datasheet, PDF (1/21 Pages) National Semiconductor (TI) – Step-up PWM DC/DC Converter Integrated with 4 Buffers

February 2004
LM3211
Step-up PWM DC/DC Converter Integrated with 4 Buffers
General Description
The LM3211 is a compact bias solution for TFT displays. It
has a current mode PWM step-up DC/DC converter with a
1.4A, 0.17Ω internal switch. Capable of generating 8V at
300mA from a Lithium Ion battery, the LM3211 is ideal for
generating bias voltages for large screen LCD panels. The
LM3211 can be operated at switching frequencies of 600kHz
or 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. The
LM3211 uses a patented internal circuitry to limit startup
inrush current of the boost switching regulator without the
use of an external softstart capacitor. An external softstart
pin enables the user to tailor the softstart to a specific
application. The LM3211 contains 4 Gamma buffers capable
of supplying 35mA source and sink. The TSSOP-20 package
ensures a low profile overall solution.
Features
n 1.4A, 0.17Ω, internal power switch
n V_IN operating range: 2.2V to 7.5V
n 600kHz/1.25MHz selectable frequency step-up DC/DC
converter
n 20 pin TSSOP package
n Inrush current limiting circuitry
n External softstart override
n 4 Gamma buffers
Applications
n LCD Bias Supplies
n Handheld Devices
n Portable Applications
n Cellular Phones/Digital Cameras
Typical Application Circuit
© 2004 National Semiconductor Corporation DS200622
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