MAX1681:125mA, Frequency-Selectable, Switched-Capacitor Voltage Converters

Up to 1MHz Switching Frequency Allows Small Capacitors

The MAX1680/MAX1681 inductorless switched-capacitor voltage converters either invert an input voltage of +2.0V to +5.5V or double it while supplying up to 125mA output current. They have a selectable-frequency option that allows the use of small capacitors: 4.7µF (MAX1680), 1µF (MAX1681). With their high output current capability, these charge-pump devices are suitable replacements for inductor-based regulators, which require more expensive external components and additional board space. The devices' equivalent output resistance (typically 3.5Ω) allows them to deliver as much as 125mA with only a 440mV drop. A shutdown feature reduces quiescent current to less than 1µA. The MAX1680/MAX1681 are available in 8-pin SO packages. For devices that deliver up to 50mA in smaller µMAX® packages, refer to the MAX860/MAX861 data sheet.

Key Features
  • Selectable Switching Frequencies:
    • 125kHz/250kHz (MAX1680)
    • 500kHz/1MHz (MAX1681)
  • Allow Use of Small Capacitors (1µF for the MAX1681)
  • 125mA Output Current
  • 3.5Ω Output Impedance
  • 1µA Logic-Controlled Shutdown
  • Configurable as Voltage Inverters or Doublers
  • +2.0V to +5.5V Input Voltage Range
  • Available in 8-Pin SO Packages
  • 90% Efficiency
MAX1680, MAX1681: Typical Operating Circuit
MAX1680, MAX1681: Typical Operating Circuit
Applications/Uses
  • Interface Power Supplies
  • Local Negative Supplies
  • MOSFET Bias
  • Op-Amp Power Supplies
DataSheet
titleDownload file
MAX1680-MAX1681 Data SheetMAX1680-MAX1681.pdf
Parametrics
Part NumberTopologyVIN
(V)
VIN
(V)
ICC
(mA)
Unadj. VOUT
(V)
IOUT
(A)
Oper. Freq.
(kHz)
Oper. Temp.
(°C)
Package/PinsBudgetary
Price
minmaxmaxtypSee Notes
MAX1680Doubler
Inverter
Unregulated
25.54.5+2xVIN
-VIN
0.125250-40 to +85SOIC(N)/8$2.29 @1k
MAX16813171000SOIC(N)/8
Quality and Environmental Data
Related Products
  • MAX860:50mA, Frequency-Selectable, Switched-Capacitor Voltage Converters
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX1681C/DNo Longer AvailableDICE SALES,;NA pin;DICE;0°C to +70°CSee data sheet
MAX1681ESANo Longer AvailableMAX1681ESA+SOIC(N),;8 pin;30.9 mm²-40°C to +85°CNo
MAX1681ESA+ActiveSOIC(N),;8 pin;30.9 mm²-40°C to +85°CLead Free
MAX1681ESA+TActiveSOIC(N),;8 pin;30.9 mm²-40°C to +85°CLead Free
MAX1681ESA-TNo Longer AvailableMAX1681ESA+TSOIC(N),;8 pin;30.9 mm²-40°C to +85°CNo
MAX1680-MAX1681.pdf MAX1681
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