MAX1920EUT+T

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. Both are available in space-saving 6-pin SOT23 packages. The MAX1920 is also available in a 6-pin TDFN package. The MAX1920/MAX1921 step-down DC-DC converters deliver over 400mA to outputs as low as 1.25V. They use a unique proprietary current-limited control scheme that maintains extremely low quiescent supply current (50μA), and their high 1.2MHz (max) operating frequency permits small, low-cost external components.

Applications

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

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