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Triple-Output TFT-LCD DC-DC Converters

Product Details

Key Features

Parametric specs for Multifunction PMICs
VIN (V) (min) 2.7
VIN (V) (max) 5.5
# Step-Up Outputs 2
# Inverting Outputs 1
VOUT (V) (min) 2.7
VOUT (V) (max) 13
Package/Pins TSSOP/16
Budgetary
Price (See Notes)
1.46
View Less

Simplified Block Diagram

Technical Docs

Data Sheet Triple-Output TFT-LCD DC-DC Converters Oct 19, 2004

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Parameters

Parametric specs for Multifunction PMICs
VIN (V) (min) 2.7
VIN (V) (max) 5.5
# Step-Up Outputs 2
# Inverting Outputs 1
VOUT (V) (min) 2.7
VOUT (V) (max) 13
Package/Pins TSSOP/16
Budgetary
Price (See Notes)
1.46

Key Features

  • Three Integrated DC-DC Converters
  • 1MHz Current-Mode PWM Boost Regulator
    • Up to +13V Main High-Power Output
    • ±1% Accuracy
    • High Efficiency (93%)
  • 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
  • 0.6mA 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 MAX1748/MAX8726 triple-output DC-DC converters in a low-profile TSSOP package provide the regulated voltages required by active-matrix, thin-film transistor (TFT) liquid-crystal displays (LCDs). One high-power DC-DC converter and two low-power charge pumps convert the +3.3V to +5V input supply voltage into three independent output voltages.

The primary 1MHz DC-DC converter generates a boosted output voltage (VMAIN) up to 13V using ultra-small inductors and ceramic capacitors. The low-power BiCMOS control circuitry and the low on-resistance (0.35Ω) of the integrated power MOSFET allows efficiency up to 93%.

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.

For both the MAX1748 and MAX8726, the supply sequence is VMAIN first, VNEG next, and finally VPOS. The MAX1748 soft-starts each supply as soon as the previous supply finishes. The MAX8726 adds a delay between the startups of VMAIN and VNEG and also between VNEG and VPOS.

The MAX1748/MAX8726 are available in the ultra-thin TSSOP package (1.1mm max height).

Simplified Block Diagram

MAX1748,MAX8726: Typical Operating Circuit MAX1748,MAX8726: Typical Operating Circuit Zoom icon

Technical Docs

Data Sheet Triple-Output TFT-LCD DC-DC Converters Oct 19, 2004

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 .