LM2702 Datasheet, PDF (1/21 Pages) National Semiconductor (TI) – TFT Panel Module

November 2002
LM2702
TFT Panel Module
General Description
The LM2702 is a compact bias solution for TFT displays. It
has a current mode PWM step-up DC/DC converter with a
2A, 0.2Ω internal switch. Capable of generating 8V at
170mA from a Lithium Ion battery, the LM2702 is ideal for
generating bias voltages for large screen LCD panels. The
LM2702 operates at a switching frequency of 600kHz allow-
ing for easy filtering and low noise. An external compensa-
tion pin gives the user flexibility in setting frequency compen-
sation, which makes possible the use of small, low ESR
ceramic capacitors at the output. The LM2702 uses a pat-
ented 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 LM2702
has an internal controllable PMOS switch used for control-
ling the row driver voltages. The switch can be controlled
externally with a control pin and delay time. The LM2702
contains a Vcom amplifier and a Gamma buffer capable of
supplying 50mA source and sink. The TSSOP-16 package
ensures a low profile overall solution.
Features
n 2A, 0.2Ω, internal power switch
n V_IN operating range: 2.2V to 12V
n 600kHz switching frequency step-up DC/DC converter
n Inrush current limiting circuitry
n External softstart override
n Internal 7.3Ω PMOS switch
n PMOS switch control pin
n PMOS switch delay pin
n Vcom amplifier
n Gamma buffer
n 16 pin TSSOP package
Applications
n LCD Bias Supplies
Typical Application Circuit
© 2002 National Semiconductor Corporation DS200511
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