MAX1878:Dual-Output Step-Down and LCD Step-Up Power Supply for PDAs

The MAX1878 dual power supply contains a step-down and step-up DC-DC converter in a small 12-pin TQFN package for use in PDAs. The step-down DC-DC converter delivers over 500mA to an output as low as 1.25V for logic power. The step-up DC-DC converter delivers over 15mA and an output as high as 28V for a liquid crystal display (LCD). With an input voltage from 2.0V to 5.5V the MAX1878 is intended for use in systems powered by a 2-cell alkaline or 1-cell lithium-ion (Li+) battery. Fast switching frequency allows the use of small inductors and capacitors, and the low 19µA typical quiescent current allows high efficiency when the system is in standby mode. Each output can be independently enabled. The MAX1878 is available in a small 0.75mm high 4mm x 4mm 12-pin TQFN package and requires no external FETs. The MAX1878 evaluation kit is available to speed designs.

Key Features
  • Evaluation Kit Available to Speed Designs
  • Two Output Voltages
    • Main Output: 1.25V to VIN
    • LCD Output: Up to 28V
  • 2.0V to 5.5V Input Range
  • Low 19µA Quiescent Supply Current
  • 1µA Shutdown Supply Current
  • High Switching Frequency for Small External Components
  • Small 0.75mm High 4mm x 4mm 12-Pin TQFN Package
MAX1878: Typical Operating Circuit
MAX1878: Typical Operating Circuit
  • GPS Receivers
  • MP3 Players
  • Organizers/Translators
  • Personal Digital Assistants (PDAs)
titleDownload file
MAX1878 Data SheetMAX1878.pdf
Part NumberPrimary TopologyMonitor/Control FeaturesDC-DC/Power FeaturesLCD/LED/Flash/CCD FeaturesVIN
Oper. Freq.
minmaxminmaxSee Notes
MAX1878Step-DownShutdownCurrent Limit
Internal Switch
Soft Start
Sync. Rectifier
TFT Bias25.51.25280.50.51000QFN/12
$1.68 @1k
Design kits & evaluation modules
Related Products
  • MAX1606:28V Internal Switch LCD Bias Supply with True Shutdown™
  • MAX1733:Low-Voltage, Step-Down DC-DC Converters in SOT23
  • MAX1734:Low-Voltage, Step-Down DC-DC Converters in SOT23
  • MAX1605:30V Internal Switch LCD Bias Supply
  • MAX1692:Low-Noise, 5.5V Input, PWM Step-Down Regulator
  • MAX1677:Compact, High-Efficiency, Dual-Output Step-Up and LCD Bias DC-DC Converter
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX1878EGCNo Longer AvailableQFN,;12 pin;16 mm²-40°C to +85°CNo
MAX1878EGC-TNo Longer AvailableQFN;12 pin-40°C to +85°CSee data sheet
MAX1878ETC+ActiveTQFN,;12 pin;16.8 mm²-40°C to +85°CLead Free
MAX1878ETC+TActiveTQFN,;12 pin;16.8 mm²-40°C to +85°CLead Free
MAX1878.pdf MAX1878
典型工作电路 MAX1878