MAX8737

The MAX8737 dual high-power linear regulator controllers use external n-channel MOSFETs to generate two independent low-voltage supplies for notebook computers. The MAX8737 delivers low output voltages from 0.5V to 2.5V (±5mV no-load accuracy). The external components allow scalable current design with loads up to 5A with excellent load regulation (1%). The regulator operates from a low input voltage, which also reduces the power dissipation in the external n-channel MOSFET. The controller powers the external MOSFET gate driver from the standard 5V system supply.

The MAX8737 includes current and thermal limits to prevent damage to the linear regulator. The MAX8737 uses an external resistive divider to fold back the current limit, reducing the overall power dissipation. The MAX8737 uses an external resistive-divider in series with the current-sense input (CS_), providing foldback current-limit protection, and effectively reducing the short-circuit power dissipation.

An output undervoltage timeout is available for low-cost applications that omit the current-sense resistor. The output undervoltage (UVP) timing depends on the magnitude of the voltage at V_OUT. The UVP detects and shuts down the LDO if the output voltage drops out of regulation. The controller uses an adjustable reference input (REFIN_) to set the nominal output voltage (V_{OUT_}), which minimizes the cost and makes the stability independent of the output voltage.

Each linear regulator features an adjustable soft-start function, and generates a delayed power-good (PGOOD) signal that signals when the linear regulator is in regulation. The MAX8737 is a low-cost solution requiring few external components and is available in a small, 4mm x 4mm, 16-pin thin QFN package.

Applications

• Low-Voltage Bias Supplies
• Notebook and Desktop Computers
• Point-of-Load Regulators
• Servers
• V_MCH and V_CCP CPU Supplies