TPS65146 Datasheet, PDF (1/30 Pages) Texas Instruments – Compact LCD Bias IC with LDO, VCOM Buffer and Reset Function

TPS65146
www.ti.com ........................................................................................................................................................................................... SLVS869 – NOVEMBER 2008
Compact LCD Bias IC with LDO, VCOM Buffer and Reset Function
FEATURES
1
• 2.5V to 6.0V Input Voltage Range
• 16.5V Boost Converter With 2A Switch Current
• 650kHz/1.2MHz Selectable Switching
Frequency
• Adjustable Soft-Start for the Boost Converter
• 500mA LDO
• Reset Function (XAO Signal)
• Regulated VGH
• Gate Voltage Shaping
• VCOM Buffer
• LCD Discharge Function
• Overvoltage Protection
• Thermal Shutdown
• Undervoltage Lockout
• 24-Pin 4×4mm QFN Package
APPLICATIONS
• Notebook PC
• Monitor
DESCRIPTION
The TPS65146 offers a very compact power supply solution designed to supply the LCD bias voltages required
by TFT (Thin Film Transistor) LCD panels running from a typical 3.3 V or 5 V supply rail. The device integrates a
step-up converter for V_S (Source Driver voltage), a positive charge pump regulator for V_GH (Gate Driver High
voltage), a logic voltage rail using an integrated LDO and a Vcom buffer driving the LCD backplane. In addition to
that, a gate voltage shaping block is integrated for V_GH, modulating the signal (into V_GHM) with high flexibility by
using a logic input VFLK and an external discharge resistor connected to RE pin. Also, an external discrete
negative charge pump can be set using the boost converter of the TPS65146 to generate V_GL (Gate Driver Low
voltage). The integrated reset function together with the LCD discharge function available in the TPS65146
provide the signals enabling the discharge of the LCD TFT pixels when powering-off. The device includes safety
features like overvoltage protection (OVP), as well as thermal shutdown.
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V_IN
3.3 V
Boost Converter
and
Over Voltage Protection
V_S
9 V/300 mA
Positive Charge Pump Regulator,
Gate Voltage Shaping
and
LCD Discharge Function
LDO
VCOM Buffer
(unity gain)
Reset function
V_GHM
20 V/10 mA
V_LVOUT
2.5 V/500 mA
V_COM
±120 mA
XAO
1
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Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2008, Texas Instruments Incorporated