Top

Low-Voltage, 400mA Step-Down DC-DC Converters in SOT23

Product Details

Key Features

Parametric specs for Step-Down Switching Regulators
VIN (V) (min) 2
VIN (V) (max) 5.5
VOUT1 (V) (min) 1.5
VOUT1 (V) (max) 3.3
IOUT1 (A) (max) 0.4
Switch Type Internal
Preset VOUT (V) 3
Output Adjust. Method Preset
Resistor
Synchronous Switching? Yes
# DC-DC Outputs 1
Switching Frequency (kHz) 1200
Package/Pins SOT23/6
Budgetary
Price (See Notes)
1.51
View Less

Simplified Block Diagram

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .

Parameters

Parametric specs for Step-Down Switching Regulators
VIN (V) (min) 2
VIN (V) (max) 5.5
VOUT1 (V) (min) 1.5
VOUT1 (V) (max) 3.3
IOUT1 (A) (max) 0.4
Switch Type Internal
Preset VOUT (V) 3
Output Adjust. Method Preset
Resistor
Synchronous Switching? Yes
# DC-DC Outputs 1
Switching Frequency (kHz) 1200
Package/Pins SOT23/6
Budgetary
Price (See Notes)
1.51

Key Features

  • 400mA Guaranteed Output Current
  • Internal Synchronous Rectifier for >90% Efficiency
  • Tiny 6-Pin SOT23 Package
  • Available in 6-Pin TDFN Package (MAX1920)
  • Up to 1.2MHz Switching Frequency for Small External Components
  • 50µA Quiescent Supply Current
  • 0.1µA Logic-Controlled Shutdown
  • 2V to 5.5V Input Range
  • Fixed 1.5V, 1.8V, 2.5V, 3V, and 3.3V Output Voltages (MAX1921)
  • Adjustable Output Voltage (MAX1920)
  • ±1.5% Initial Accuracy
  • Soft-Start Limits Startup Current
  • Applications/Uses

    • Battery-Powered Applications
    • CDMA Power Amplifier Supply
    • Next-Generation Wireless handsets
    • PDAs, Palmtops, and Handy Terminals

    Description

    The MAX1920/MAX1921 step-down converters deliver over 400mA to outputs as low as 1.25V. These converters use a unique proprietary current-limited control scheme that achieves over 90% efficiency. These devices maintain extremely low quiescent supply current (50µA), and their high 1.2MHz (max) operating frequency permits small, low-cost external components. This combination makes the MAX1920/MAX1921 excellent high-efficiency alternatives to linear regulators in space-constrained applications.

    Internal synchronous rectification greatly improves efficiency and eliminates the external Schottky diode required in conventional step-down converters. Both devices also include internal digital soft-start to limit input current upon startup and reduce input capacitor requirements.

    The MAX1920 provides an adjustable output voltage (1.25V to 4V). The MAX1921 provides factory-preset output voltages (see the Selector Guide). Both are available in space-saving 6-pin SOT23 packages. The MAX1920 is also available in a 6-pin TDFN package.

    Simplified Block Diagram

    MAX1920, MAX1921: Typical Operating Circuit MAX1920, MAX1921: Typical Operating Circuit Zoom icon

    Technical Docs

    Support & Training

    Search our knowledge base for answers to your technical questions.

    Filtered Search

    Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .