PRODUCT DESCRIPTION
The SPX1581 is a 5A Low Dropout Regulator with extremely low dropout voltage. The adjustable version requires only two external resistors to set the output voltage. The fixed version has a preset output of 3.3V, 2.8V or 2.5V and does not require any external resistors. The SPX1581 features a low dropout of less than 400mV(typ.) and offers fast transient response. This device is suitable for Pentium applications requiring 2.8V or 2.5V from 3.3V ATX power supplies, where a low current input voltage 1V greater than the output voltage is needed. With an external sense pin the load regulation is less than 1mV. This device is an excellent choice for the use in powering low voltage microprocessors that require a lower dropout, fast transient response to regulate from 3.3V and 5V supplies. The SPX1581 is also an excellent choice as a post regulator for switching supplies applications.

FEATURES
• Low Dropout Voltage 500mV at 5A Full Load Current
• Adjustable Output Down to 1.2V from ATX Power Supply
• Fixed Output Voltages of 3.3V, 2.8V & 2.5V
• Extremely Tight Voltage and Line Regulation
• Standard 5-Terminal Low Cost TO-220 & TO-263

APPLICATIONS
• 3.3V to 2.8V ATX Power Supplies
• 3.3V to 2.9V for Portable PENTIUM Processor
• 5V to 3.5V VRE Supply
• High Efficiency “Green” Computer Systems