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MAX1556, MAX1556A

16µA IQ, 1.2A PWM Step-Down DC-DC Converters

16µA Quiescent Current, 1.2A and 600mA, Step-Down Converters are 95% Efficient at 1mA

Product Details

Key Features

Applications/Uses

Parametric specs for Step-Down Switching Regulators
VIN (V) (min) 2.6
VIN (V) (max) 5.5
VOUT1 (V) (min) 0.75
VOUT1 (V) (max) 5.5
IOUT1 (A) (max) 1.2
Switch Type Internal
Preset VOUT (V) 1.8
2.5
3.3
Output Adjust. Method Preset
Resistor
Synchronous Switching? Yes
# DC-DC Outputs 1
Switching Frequency (kHz) 1000
Package/Pins TDFN/10
Budgetary
Price (See Notes)
1.74
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Simplified Block Diagram

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Parameters

Parametric specs for Step-Down Switching Regulators
VIN (V) (min) 2.6
VIN (V) (max) 5.5
VOUT1 (V) (min) 0.75
VOUT1 (V) (max) 5.5
IOUT1 (A) (max) 1.2
Switch Type Internal
Preset VOUT (V) 1.8
2.5
3.3
Output Adjust. Method Preset
Resistor
Synchronous Switching? Yes
# DC-DC Outputs 1
Switching Frequency (kHz) 1000
Package/Pins TDFN/10
Budgetary
Price (See Notes)
1.74

Key Features

  • Up to 97% Efficiency
  • 95% Efficiency at 1mA Load Current
  • Low 16µA Quiescent Current
  • 1MHz PWM Switching
  • Tiny 3.3µH Inductor
  • Selectable 3.3V, 2.5V, 1.8V, 1.5V, 1.3V, 1.2V, 1.0V, and Adjustable Output
  • 1.2A Guaranteed Output Current (MAX1556/MAX1556A)
  • Voltage Positioning Optimizes Load-Transient Response
  • Low 27µA Quiescent Current in Dropout
  • Low 0.1µA Shutdown Current
  • No External Schottky Diode Required
  • Analog Soft-Start with Zero Overshoot Current
  • Small, 10-Pin, 3mm x 3mm TDFN Package

Applications/Uses

  • Cell Phones/Smartphones
  • Digital Cameras and Camcorders
  • Handheld Instruments
  • PDAs and Palmtop Computers
  • Portable MP3 and DVD Players

Description

The MAX1556/MAX1556A/MAX1557 are low-operating-current (16µA), fixed-frequency step-down regulators. High efficiency, low-quiescent operating current, low dropout, and minimal (27µA) quiescent current in dropout make these converters ideal for powering portable devices from 1-cell Li-ion or 3-cell alkaline/NiMH batteries. The MAX1556 delivers up to 1.2A; has pin-selectable 1.8V, 2.5V, and 3.3V outputs; and is also adjustable. The MAX1557 delivers up to 600mA; has pin-selectable 1V, 1.3V, and 1.5V outputs; and is also adjustable.

The MAX1556/MAX1556A/MAX1557 contain a low-on-resistance internal MOSFET switch and synchronous rectifier to maximize efficiency and dropout performance while minimizing external component count. A proprietary topology offers the benefits of a high fixed-frequency operation while still providing excellent efficiency at both light and full loads. A 1MHz PWM switching frequency keeps components small. Both devices also feature an adjustable soft-start to minimize battery transient loading.

The MAX1556/MAX1556A/MAX1557 are available in a tiny 10-pin TDFN (3mm x 3mm) package.

Simplified Block Diagram

MAX1556, MAX1557: Typical Operating Circuit MAX1556, MAX1557: 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 .