MAX1748

Triple-Output TFT-LCD DC-DC Converters


Please check latest availability status for a specific part variant.

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).
MAX1748,MAX8726: Typical Operating Circuit MAX1748,MAX8726: Typical Operating Circuit Enlarge+

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

See parametric specs for Multifunction PMICs (81)


Part NumberPrimary TopologyMonitor/Control FeaturesDC-DC/Power FeaturesLCD/LED/Flash/CCD FeaturesVIN
(V)
VIN
(V)
VOUT
(V)
VOUT
(V)
Max. IOUT
(A)
Max. IOUT
(A)
Oper. Freq.
(kHz)
Inverting OutputsPackage/PinsBudgetary
Price
minmaxminmaxSee Notes
MAX1748 Step-UpShutdown
Fixed Freq./PWM
Internal Switch
Soft Start
TFT Bias2.75.52.7130.50.510001
TSSOP/16
$1.38 @1k

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

MAX1748EVKIT: Evaluation Kit for the MAX1748, MAX1779

Technical Documents

Tutorial 671 Energy Management for Small Portable Systems
Product Reliability Reports: MAX1748.pdf 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

Quality Management System >
Environmental Management System >

 
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