LT1943 - High Current Quad Output Regulator for TFT LCD Panels


  • 4 Integrated Switches: 2.4A Buck, 2.6A Boost,
  • 0.35A Boost, 0.35A Inverter (Guaranteed Minimum Current Limit)
  • Fixed Frequency, Low Noise Outputs
  • Soft-Start for all Outputs
  • Externally Programmable VON Delay
  • Integrated Schottky Diode for VON Output
  • PGOOD Pin for AVDD Output Disconnect
  • 4.5V to 22V Input Voltage Range
  • PanelProtectTM Circuitry Disables VON Upon Fault
  • Available in Thermally Enhanced 28-Lead TSSOP

Typical Application

LT1943 Typical Application
LT1943 Typical Application


The LT1943 quad output adjustable switching regulator provides power for large TFT LCD panels. The device, housed in a low profile 28 pin thermally enhanced TSSOP package, can generate a 3.3V or 5V logic supply along with the triple output supply required for the TFT LCD panel. Operating from an input range of 4.5V to 22V, a step-down regulator provides a low voltage output VLOGIC with up to 2A current. A high-power step-up converter, a lowerpower step-up converter and an inverting converter provide the three independent output voltages AVDD, VON and VOFF required by the LCD panel. A high-side PNP provides delayed turn-on of the VON signal and can handle up to 30mA. Protection circuitry ensures that VON is disabled if any of the four outputs are more than 10% below the programmed voltage.

All switchers are synchronized to an internal 1.2MHz clock, allowing the use of low profile inductors and ceramic capacitors throughout. A current mode architecture provides excellent transient response. For best flexibility, all outputs are adjustable. Soft-start is included in all four channels. A PGOOD pin can drive an optional PMOS pass device to provide output disconnect for the AVDD output.


CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LT1943EFE#PBF TSSOP-28 FE E 05-08-1663 (EB) Yes
LT1943EFE#TRPBF TSSOP-28 FE E 05-08-1663 (EB) Yes

LT1943 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
LT1943EFE#PBF TSSOP-28 E $6.69 $4.75 Yes
LT1943EFE#TRPBF TSSOP-28 E $4.87 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC620A LT1943EFE | 4-Output Sw. Reg. For TFT-LCD Panels, Vin = 8-20V, Vout = 3.3V @ 2A, 13V @ 500mA, 30V @ 30mA, -10V @ 50mA $150.00
DC697A LT1943EFE | 4-Output Switching Regulator For TFT-LCD Panels, Vin = 4.5V - 8V, Vout = 3.3V @ 1.5A, 13V @ 500mA, 30V @ 20mA, -10V @ 50mA $150.00
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Click here to view our complete list of demo boards


  • Large TFT-LCD Desktop Monitors
  • Flat Panel Televisions

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