AMS1117-3.3

AMS1117 is a positive-voltage-output low-dropout three-terminal linear voltage regulator with a dropout voltage of 1.2V at 1A output current. AMS1117 is available in two versions: fixed voltage output and adjustable voltage output. The fixed output voltages of 1.5V, 1.8V, 2.5V, 3.3V, 5.0V, and the adjustable version offer a voltage accuracy of 1.5%; the fixed 1.2V version has an output voltage accuracy of 2%. AMS1117 integrates internal over-temperature protection and current limiting circuits, suitable for a wide range of electronic products. AMS1117 is a low-dropout voltage regulator whose pass element consists of an NPN transistor driven by a PNP transistor. The dropout voltage is defined as: VDROP = VBE + VSAT. AMS1117 is available in both fixed and adjustable versions, with output voltages of: 1.2V, 1.5V, 1.8V, 2.5V, 3.3V, and 5.0V. An on-chip thermal shutdown circuit provides overload and over-temperature protection against excessive junction temperatures caused by ambient temperature conditions. To ensure stability of the AMS1117, the adjustable version requires a tantalum capacitor of at least 22μF connected at the output. For the fixed voltage versions, a smaller capacitor may be used, depending on the specific application. In general, the stability of a linear regulator decreases as the output current increases.

Applications

• Laptops, PDAs, and notebook computers
• Battery chargers
• SCSI-II active terminators
• Mobile phones
• Cordless phones
• Battery-powered systems
• Portable devices
• Post-regulator for switching power supplies

Key features

• Fixed output voltage versions (1.5V, 1.8V, 2.5V, 3.3V, 5.0V) and adjustable version: 1.5% output voltage accuracy
• Fixed 1.2V output voltage accuracy: 2%
• Low dropout voltage: 1.2V at 1A output current
• Current limiting
• Thermal shutdown
• Temperature range: -40℃ ~ 125℃