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Low-Power Triple-Output TFT LCD DC-DC Converter

Industry's-First High-Performance Boost Regulator with Dual Charge-Pump Regulators for Small-Sized Battery-Powered LCD Applications

Product Details

The MAX1779 triple-output DC-DC converter provides highly efficient regulated voltages required by small active matrix, thin-film transistor (TFT) liquid-crystal displays (LCDs). One high-power DC-DC converter and two low-power charge pumps convert the +2.7V to +5.5V input supply voltage into three independent output voltages.

The primary high-power DC-DC converter generates a boosted output voltage (VMAIN) up to 13V that is regulated within ±1%. The low-power BiCMOS control circuitry and the low on-resistance (1 ohm) of the integrated power MOSFET allows efficiency up to 91%. The 250kHz current-mode pulse-width modulation (PWM) architecture provides fast transient response and allows the use of ultra-small inductors and ceramic capacitors.

The dual charge pumps independently regulate one positive output (VPOS) and one negative output (VNEG). These low-power outputs use external diode and capacitor stages (as many stages as required) to regulate output voltages up to +40V and down to -40V. A proprietary regulation algorithm minimizes output ripple, as well as capacitor sizes for both charge pumps.

The MAX1779 is available in the ultra-thin TSSOP package (1.1mm max height).

Key Features

  • Three Integrated DC-DC Converters
  • 250kHz Current-Mode PWM Boost Regulator
    • Up to +13V Main High-Power Output
    • ±1% Accuracy
    • High Efficiency (91%)
  • Dual Charge-Pump Outputs
    • Up to +40V Positive Charge-Pump Output
    • Down to -40V Negative Charge-Pump Output
  • Internal Supply Sequencing
  • Internal Power MOSFETs
  • +2.7V to +5.5V Input Supply
  • 0.1µA Shutdown Current
  • 0.5mA Quiescent Current
  • Internal Soft-Start
  • Power-Ready Output
  • Ultra-Small External Components
  • Thin TSSOP Package (1.1mm max)

Applications/Uses

  • Camcorders
  • Digital Still Cameras
  • Passive-Matrix LCD Displays
  • PDAs
  • TFT Active-Matrix LCD Displays

Simplified Block Diagram

MAX1779: Typical Operating Circuit MAX1779: Typical Operating Circuit Zoom icon

Technical Docs

Design & Development

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Additional Resources
MAX1748EVKIT
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Parameters

Key Features

  • Three Integrated DC-DC Converters
  • 250kHz Current-Mode PWM Boost Regulator
    • Up to +13V Main High-Power Output
    • ±1% Accuracy
    • High Efficiency (91%)
  • Dual Charge-Pump Outputs
    • Up to +40V Positive Charge-Pump Output
    • Down to -40V Negative Charge-Pump Output
  • Internal Supply Sequencing
  • Internal Power MOSFETs
  • +2.7V to +5.5V Input Supply
  • 0.1µA Shutdown Current
  • 0.5mA Quiescent Current
  • Internal Soft-Start
  • Power-Ready Output
  • Ultra-Small External Components
  • Thin TSSOP Package (1.1mm max)

Applications/Uses

  • Camcorders
  • Digital Still Cameras
  • Passive-Matrix LCD Displays
  • PDAs
  • TFT Active-Matrix LCD Displays

Description

The MAX1779 triple-output DC-DC converter provides highly efficient regulated voltages required by small active matrix, thin-film transistor (TFT) liquid-crystal displays (LCDs). One high-power DC-DC converter and two low-power charge pumps convert the +2.7V to +5.5V input supply voltage into three independent output voltages.

The primary high-power DC-DC converter generates a boosted output voltage (VMAIN) up to 13V that is regulated within ±1%. The low-power BiCMOS control circuitry and the low on-resistance (1 ohm) of the integrated power MOSFET allows efficiency up to 91%. The 250kHz current-mode pulse-width modulation (PWM) architecture provides fast transient response and allows the use of ultra-small inductors and ceramic capacitors.

The dual charge pumps independently regulate one positive output (VPOS) and one negative output (VNEG). These low-power outputs use external diode and capacitor stages (as many stages as required) to regulate output voltages up to +40V and down to -40V. A proprietary regulation algorithm minimizes output ripple, as well as capacitor sizes for both charge pumps.

The MAX1779 is available in the ultra-thin TSSOP package (1.1mm max height).

Simplified Block Diagram

MAX1779: Typical Operating Circuit MAX1779: Typical Operating Circuit Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal