SOT23, Switched-Capacitor Voltage Inverters with Shutdown

Smallest, High-Efficiency Bias for Small LCD/GaAsFET PA Bias: Small Cap Size, No Inductors and Low Supply Current

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The ultra-small MAX1719/MAX1720/MAX1721 monolithic, CMOS charge-pump inverters accept input voltages ranging from +1.5V to +5.5V. The MAX1720 operates at 12kHz, and the MAX1719/MAX1721 operate at 125kHz. High efficiency, small external components, and logic-controlled shutdown make these devices ideal for both battery-powered and board-level voltage conversion applications.

Oscillator control circuitry and four power MOSFET switches are included on-chip. A typical MAX1719/MAX1720/MAX1721 application is generating a -5V supply from a +5V logic supply to power analog circuitry. All three parts come in a 6-pin SOT23 package and can deliver a continuous 25mA output current.

For pin-compatible SOT23 switched-capacitor voltage inverters without shutdown (5-pin SOT23), see the MAX828/MAX829 and MAX870/MAX871 data sheets. For applications requiring more power, the MAX860/MAX861 deliver up to 50mA. For regulated outputs (up to -2 x VIN), refer to the MAX868. The MAX860/MAX861 and MAX868 are available in space-saving µMAX® packages.
MAX1719, MAX1720, MAX1721: Typical Operating Circuit MAX1719, MAX1720, MAX1721: Typical Operating Circuit Enlarge+

Key Features

  • 1nA Logic-Controlled Shutdown
  • 6-Pin SOT23 Package
  • 99.9% Voltage Conversion Efficiency
  • 50µA Quiescent Current (MAX1720)
  • +1.5V to +5.5V Input Voltage Range
  • 25mA Output Current
  • Requires Only Two 1µF Capacitors (MAX1719/MAX1721)


  • Battery-Powered Applications
  • GaAs PA Bias Supply
  • Handy-Terminals, PDAs
  • Local Negative Supply from a Positive Supply
  • Small LCD Panels

See parametric specs for Charge Pumps (45)

Part NumberTopologyVIN
Unadj. VOUT
Oper. Freq.
Oper. Temp.
minmaxmaxtypSee Notes
Unregulated to +85
$0.75 @1k
MAX1720 0.0912
$0.76 @1k
MAX1721 0.65125
$0.75 @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.

Technical Documents

Tutorial 725 DC-DC Conversion Without Inductors
Request Reliability Report for: MAX1719 
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.

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