2SD1666-R Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 60 V
• Collector-Base Voltage, max: 60 V
• Emitter-Base Voltage, max: 6 V
• Collector Current − Continuous, max: 3 A
• Collector Dissipation: 25 W
• DC Current Gain (h_fe): 100 to 200
• Transition Frequency, min: 40 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-220F

Here is an image showing the pin diagram of this transistor.The 2SD1666-R transistor can have a current gain of 100 to 200. The gain of the 2SD1666 will be in the range from 70 to 280, for the 2SD1666-Q it will be in the range from 70 to 140, for the 2SD1666-S it will be in the range from 140 to 280.Sometimes the "2S" prefix is not marked on the package - the 2SD1666-R might only be marked "D1666-R".The complementary PNP transistor to the 2SD1666-R is the 2SB1133-R.The BDP949 (SOT-223) is the SMD version of the 2SD1666-R transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the 2SD1666-R with the 2SC1826, 2SC1827, 2SC1985, 2SC1986, 2SC2075, 2SC2078, 2SC2078E, 2SC2334, 2SC2527, 2SC3179, 2SC3252, 2SC3252-R, 2SC3253, 2SC3253-R, 2SC3254, 2SC3254-R, 2SC3255, 2SC3255-R, 2SC3258, 2SC3308, 2SC3346, 2SC3540, 2SC3710, 2SC3710A, 2SC3746, 2SC3746-R, 2SC3747, 2SC3747-R, 2SC3748, 2SC3748-R, 2SC3834, 2SC3851, 2SC3851A, 2SC4007, 2SC4007-E, 2SC4008, 2SC4008-E, 2SC4153, 2SC4550, 2SC4550-M, 2SC4551, 2SC4551-M, 2SC4552, 2SC4552-M, 2SC789, 2SD1134, 2SD1134-C, 2SD1266, 2SD1266A, 2SD1267, 2SD1267A, 2SD1268, 2SD1269, 2SD1270, 2SD1271, 2SD1274, 2SD1274A, 2SD1274B, 2SD1354, 2SD1354-Y, 2SD1355, 2SD1356, 2SD1362, 2SD1406, 2SD1406-Y, 2SD1407, 2SD1407A, 2SD1408, 2SD1411, 2SD1411A, 2SD1568, 2SD1568-K, 2SD1588, 2SD1588-K, 2SD1761, 2SD1761-E, 2SD1913, 2SD1913R, 2SD2012, 2SD2058, 2SD2058-Y, 2SD2059, 2SD2060, 2SD2061, 2SD2374, 2SD2374A, 2SD2394, 2SD2394-E, 2SD313, 2SD313E, 2SD363, 2SD476A, 2SD476A-C, 2SD525, 2SD526, 2SD568, 2SD568-K, 2SD569, 2SD569-K, 2SD613, 2SD613-E, 2SD743, 2SD743-Q, 2SD743A, 2SD743A-Q, 2SD812, 2SD812-P, 2SD823, 2SD856, 2SD856A, 2SD857, 2SD857A, 2SD866, 2SD866A, 2SD880, 2SD880Y, BD203, BD241A, BD241B, BD241C, BD243A, BD243B, BD243C, BD303, BD535, BD537, BD539A, BD539B, BD539C, BD539D, BD543A, BD543B, BD543C, BD545A, BD545B, BD545C, BD797, BD799, BD801, BD807, BD809, BD935, BD935F, BD937, BD937F, BD939, BD939F, BD941, BD941F, BD949, BD951, BD953, BD955, BDT81, BDT81F, BDT83, BDT83F, BDT85, BDT85F, BDT87, BDT87F, BDT91, BDT91F, BDT93, BDT93F, BDT95, BDT95F, BDX77, D44H11, D44H11FP, D44H8, KSC2334, KSD1406, KSD1406-Y, KSD1408, KSD1588, KSD1588-Y, KSD2012, KSD2012-Y, KSD2058, KSD2058-Y, KSD363, KSD526, KSD568, KSD568-Y, KSD569, KSD569-Y, KSD880, KSD880-Y, KTC2016, KTC2016-Y, KTC2018, KTC2026, KTC2026-Y, KTC2026Y, KTC2027, KTC2028, KTD1351, KTD1351Y, KTD2058, KTD2058Y, KTD2059, KTD2060, MJE15028, MJE15028G, NTE152, TIP41D or TIP42D.