2N3904 SMALL SIGNAL TRANSISTORS (NPN) FEATURES ¤ NPN Silicon Epitaxial Planar Transistor for switching and amplifier applications. ¤ As complementary type, the PNP transistor 2N3906 is recommended. ¤ On special request, this transistor is also manufactured in the pin configuration TO-18. ¤ This transistor is also available in the SOT-23 case Nov 30, 2015 · The main difference is in Ft; typically 1100MHz for the SS9018 and 300MHz for the 2N3904. There are different rules-of-thumb for amplifiers; one says that Ft should be five times the required upper frequency. On that basis the 2N3904 is suitable for up to about 60MHz whilst the SS9018 will serve at over 200MHz. 2N3904 NPN SILICON TRANSISTOR UNISONIC TECHNOLOGIES CO., LTD 4 of 4 www.unisonic.com.tw QW-R201-027.G TYPICAL CHARACTERISTICS(Cont.) UTC assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or 2N3904 / MMBT3904 / PZT3904. NPN General Purpose Amplifier (continued) Typical Characteristics (continued) Storage Time vs Collector Current. 1 10 100 2N3904 MMBT390 4 MMPQ390 4 PZT3904 NPN General Purpose Amplifier This device is designed as a general purpose amplif ier and switch. The useful dynamic range extends to 100 mA as a swi tch and to 100 MHz as an amplifier. Sourced from Process 23. Absolute Maximum Ratings* TA = 25°C unless otherwise noted Figure 2: 2N3904 circuit example - drawn in Scheme-it®. Since the 2N3904 is an NPN transistor, that means the base needs positive biasing (appropriate voltage levels and resistance) to turn on the collector emitter junction for proper current flow.