2SD666A Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 100 V
• Collector-Base Voltage, max: 120 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 0.05 A
• Collector Dissipation: 0.9 W
• DC Current Gain (h_fe): 60 to 200
• Transition Frequency, min: 140 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-92MOD

Here is an image showing the pin diagram of this transistor.The 2SD666A transistor can have a current gain of 60 to 200. The gain of the 2SD666A-B will be in the range from 60 to 120, for the 2SD666A-C it will be in the range from 100 to 200.Sometimes the "2S" prefix is not marked on the package - the 2SD666A might only be marked "D666A".The complementary PNP transistor to the 2SD666A is the 2SB646A.You can replace the 2SD666A with the 2SC1473, 2SC1573, 2SC2383, 2SC3228, 2SC3244, 2SC3467, 2SD667A, 2SD668A, HSD1609S, KSC1009C, KSC2310, KSC2383 or KTC3228.