General Description

The MAX8560/MAX8561/MAX8562 step-down DC-DC converters are optimized for applications that prioritize small size and high efficiency. They utilize a proprietary hysteretic-PWM control scheme that switches with fixed frequency and is adjustable up to 4MHz, allowing customers to trade efficiency for smaller external components. Output current is guaranteed up to 500mA, while quiescent current is only 40µA (typ).

Internal synchronous rectification greatly improves efficiency and eliminates the external Schottky diode required in conventional step-down converters. Built-in soft-start eliminates inrush current to reduce input capacitor requirements. The MAX8561 features logic controlled output voltage, while the MAX8562 drives an external bypass FET.

The MAX8560 is available in a 5-pin Thin SOT23 package. The MAX8561/MAX8562 are available in space saving 8-pin 3mm x 3mm Thin DFN packages.

Features

♦ Up to 4MHz PWM Switching Frequency

♦ 500mA Guaranteed Output Current

♦ 40µA (typ) Quiescent Current

♦ Adjustable Output Voltage from 0.6V to 2.5V

♦ Logic-Controlled Output Voltage (MAX8561)

♦ Drives External Bypass FET (MAX8562)

♦ ±1.5 Initial Accuracy

♦ Soft-Start Eliminates Inrush Current

♦ Fast Voltage-Positioning Transient Response

♦ Internal Synchronous Rectifier

♦ 2.7V to 5.5V Input

♦ 0.1µA Logic-Controlled Shutdown

♦ Thermal Shutdown

♦ Thin SOT23 or Space-Saving 3mm x 3mm x 0.8mm TDFN Packages

Applications

   Microprocessor/DSP Core Supplies

   Cellular and Smart Phones

   CDMA/RF Power-Amplifier Supplies

   PDAs, DSC, and MP3 Players