General Description

The MAX1540/MAX1541 dual pulse-width modulation (PWM) controllers provide the high efficiency, excellent transient response, and high DC-output accuracy necessary for stepping down high-voltage batteries to generate low-voltage chipset and RAM power supplies in notebook computers.

Features

♦ Inductor-Saturation Protection

♦ Accurate Differential Current-Sense Inputs

♦ Dual Ultra-High-Efficiency Quick-PWMs with 100ns Load-Step Response

♦ MAX1540

    1.8V/1.2V Fixed or 0.7V to 5.5V Adjustable Output (OUT1)

    2.5V/1.5V Fixed or 0.7V to 5.5V Adjustable Output (OUT2)

    Fixed 5V, 100mA Linear Regulator

♦ MAX1541

    External Reference Input (REFIN1)

    Dynamically Selectable Output Voltage—0.7V

    to 5.5V (OUT1)

    2.5V/1.8V Fixed or 0.7V to 5.5V Adjustable Output (OUT2)

    Optional Power-Good and Fault Blanking During Transitions

    Fixed 5V or Adjustable 100mA Linear Regulator

♦ 1 VOUT Accuracy over Line and Load

♦ 2V to 28V Battery Input Range

♦ 170kHz to 620kHz Selectable Switching Frequency

♦ Overvoltage/Undervoltage-Protection Option

♦ 1.7ms Digital Soft-Start

♦ Drives Large Synchronous-Rectifier FETs

♦ 2V ±0.7 Reference Output

♦ Separate Power-Good Window Comparators

Applications

    Notebook Computers

    Core/IO Supplies as Low as 0.7V

    0.7V to 5.5V Supply Rails

    CPU/Chipset/GPU with Dynamic Voltage Core Supplies (MAX1541)

    DDR Memory Termination (MAX1541)

    Active Termination Buses (MAX1541)