50mA, Regulated, Step-Down Charge Pump for 1.8V or 1.9V Logic

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The MAX1730 regulated step-down charge pump generates up to 50mA at fixed output voltages of 1.8V or 1.9V from an input voltage in the 2.7V to 5.5V range. Specifically designed to provide high-efficiency logic supplies in applications that demand a compact design, the MAX1730 employs fractional conversion techniques to provide efficiency exceeding that of a linear regulator.

The MAX1730 operates at up to 2MHz, permitting the use of small 0.22µF flying capacitors while maintaining low 75µA quiescent supply current. Proprietary soft-start circuitry prevents excessive current from being drawn from the supply during startup, making the MAX1730 compatible with higher impedance sources such as alkaline and lithium-ion cells.

The MAX1730 is available in a space-saving 10-pin µMAX® package that is only 1.09mm high and occupies one-half the area of an 8-pin SO.
MAX1730: Typical Operating Circuit MAX1730: Typical Operating Circuit Enlarge+

Key Features

  • > 85% Peak Efficiency
  • 50mA Guaranteed Output Current
  • Dual-Mode 1.8V or 1.9V Output
  • ±3% Output Voltage Accuracy
  • Up to 2MHz Operating Frequency
  • Small 0.22µF Capacitors
  • No Inductor Required
  • 2.7V to 5.5V Input Voltage Range
  • Output Disconnects from Input in Shutdown Mode
  • Small 10-Pin µMAX Package (1.09mm max height)


  • Handheld Instruments (PDAs, Palmtops)
  • Low-Voltage Logic Supplies
  • PC Cards
  • PDAs
  • Wireless Handsets

See parametric specs for Charge Pumps (45)

Part NumberTopologyVIN
Unadj. VOUT
Oper. Freq.
Oper. Temp.
minmaxmaxtypSee Notes
MAX1730 Regulated2.75.50.15
0.052000-40 to +85
$1.52 @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.
Request Reliability Report for: MAX1730 
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