Quad Output Regulator protects TFT panels.
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Press Release Summary:
Housed in TSSOP-28 package, LT1943 adjustable switching regulator is suited for 22 in. and larger TFT LCD applications. It operates from 4.5-22 V input range, delivering independent outputs for VLOGIC, AVDD, VON, and VOFF. Unit contains 2.4 A buck regulator, 2.6 A boost regulator, TFT biasing output, and inverter. All switchers are synchronized to internal 1.2 MHz clock. It also offers Panel Protect(TM) feature, PNP transistor, PGOOD output, and soft start option for all channels.
Original Press Release:
High Current Quad Output Regulator Provides Optimal Protection for Large TFT Panels
MILPITAS, CA - December 23, 2003 - Linear Technology announces the LT1943, a high current, quad output, adjustable switching regulator developed specifically for 22" and larger TFT LCD applications. It operates from an input range of 4.5V to 22V, delivering independent outputs for VLOGIC, AVDD, VON, and VOFF as required by TFT LCD applications. The LT1943 contains a 2.4A buck regulator to power VLOGIC, a 2.6A boost regulator to drive TFTs, a high voltage TFT biasing output and an inverter for negative TFT biasing. All of the switchers are synchronized to an internal 1.2MHz clock, keeping switching noise out of critical audio bands and enabling the use of low profile inductors and tiny ceramic input and output capacitors. Its TSSOP-28E exposed pad package and tiny externals provide a very compact, low profile, thermally efficient footprint.
Several features of the LT1943 set it apart from modules and other less integrated solutions previously found in TFT LCD applications. First is the Panel ProtectTM feature. This feature disables VON if any of the four outputs are more than 10% below the normal re-set output voltage. This prevents the TFT panel from being exposed to an inrush of VON current and effectively "flash lighting" the entire TFT panel, creating damage to the panel. A high side PNP transistor provides a delayed turn-on of the VON signal to insure it comes on only after all the other outputs are powered up. The VON signal can provide up to 30mA of bias current enabling it to drive large panels. A PGOOD output is also included to drive an optional PMOS pass device to provide output disconnect for the AVDD output. Soft start is also available for all channels to create a carefully controlled power sequencing of the panel at turn-on and is programmable via an external capacitors. The LT1943's high level of integration offers TFT LCD designers the most compact, highly integrated power solution available.
The LT1943EFE is available from stock in a 28-Lead TSSOP package. Pricing starts at $4.75 each for 1,000-piece quantities.
Summary of Features: LT1943
4 Integrated Switches: 2.4A Buck, 2.6A Boost, 0.3A Boost, 0.4A Inverter
Fixed Frequency, 1.2MHz Operation
Panel Protect TM Disables VON Upon Fault Detection
Adjustable Soft-Start for All Outputs
Integrated Schottky Diode for VON Output
PGOOD Pin for AVDD Output Disconnect
4.5V to 22V Input Voltage Range
Thermally Enhanced TSSOP-28 Package
Company Background
Linear Technology Corporation was founded in 1981 as a manufacturer of high performance linear integrated circuits. Linear Technology products include operational, instrumentation and audio amplifiers; voltage regulators,power management devices, DC-DC converters and voltage references; comparators; monolithic filters; communications interface circuits; one-chip data acquisition sub-systems; pulse-width modulators and sample-and-hold devices; and high frequencydevices. Applications for Linear Technology's high performance circuits include wireless and broadband telecommunications infrastructure, cellular telephones, networking products and satellite systems, notebook and desk top computers, computer peripherals, video/multimedia, industrial and medical instrumentation, automotive electronics, factory automation, process control, military and space systems, and high-end consumer products including digital cameras, MP3 players and other electronic products.
Note: LT, AND LTC are registered trademarks of Linear Technology Corp.
