The SPX1121N-3.3 is a low dropout (LDO) linear regulator from Sipex Corporation (now part of Exar). It's designed to provide a fixed 3.3V output voltage with a maximum output current of 500mA. Its low dropout characteristic allows it to maintain regulation even when the input voltage is only slightly higher than the output voltage.

Applications:

• Post regulators for switching power supplies
• Powering microcontrollers and microprocessors
• Battery-powered devices
• Portable electronic devices
• Voltage regulation in communication equipment

Features:

• Fixed 3.3V output voltage
• Low dropout voltage (typically around 200mV at 500mA)
• 500mA output current capability
• Overcurrent and overtemperature protection
• Available in a compact package (e.g., TO-252)

Benefits:

• Provides a stable 3.3V supply for sensitive electronic components.
• Extends battery life in portable applications due to its low dropout characteristic.
• Protects the regulator and connected circuitry from damage due to overload or overheating.
• Enables smaller and more efficient power supply designs.
• Simple to use with minimal external components required.

Technical Specifications:

The SPX1121N-3.3 provides a fixed output voltage of 3.3V with a specified accuracy. The input voltage range is typically from slightly above 3.3V up to a maximum limit. The dropout voltage is typically specified at a given output current (e.g., 200mV at 500mA). It features overcurrent and thermal shutdown protection. It comes in a variety of packages, such as TO-252. Refer to the official Sipex/Exar datasheet for precise specifications, including the input voltage range, dropout voltage characteristics at different currents, thermal resistance, and recommended external capacitors for stability.