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2SC1815Y is an NPN general-purpose transistor manufactured by NEC (now integrated into Renesas Electronics). This transistor is sometimes used in low power amplifiers and switching circuits.
The 2SC1815Y has low noise and high gain, and is housed in a small plastic package, SOT-23, which provides great design flexibility and is suitable for miniaturized applications. This transistor is commonly used in applications such as audio amplifiers, RF amplifiers, switching circuits, LED drivers, and sensors.
The 2SC1815Y is a well-known general-purpose transistor and many electronic component manufacturers produce equivalents.