The MMBT5551 is a surface-mounted, RoHS-compliant NPN and PNP transistor manufactured by KEXIN. It is part of a low voltage, low current, SOT23 package, ideal for power management, low noise and linear applications. It offers high current gain, low noise performance and long-term stability, which makes it suitable for a wide range of applications including RF power amplifiers and analog switches. It features a high breakdown voltage, low saturation voltage and pulse current capability.