High-reliability discrete products and engineering services since 1977 2N2646, 2N2647 SILICON UNIJUNCTION TRANSISTOR FEATURES Available as “HR” (high reliability) screened per MIL-PRF-19500, JANTX level. Add “HR” suffix to base part number. Available as non-RoHS (Sn/Pb plating), standard, and as RoHS by adding “-PBF” suffix. MAXIMUM RATINGS Rating (1) Power dissipation Symbol Value Unit PD 300 mW IE(EMS) 50 mA IE 2 Amps Emitter reverse voltage VB2E 30 Volts Interbase voltage VB2B1 35 Volts Operating junction temperature range TJ -65 to 125 °C Storage temperature range Tstg -65 to 150 °C RMS emitter current Peak pulse emitter current (2) Note 1: Derate 3mW/°C increase in ambient temperature. The total power dissipation must be limited by the external circuitry. Note 2: Capacitor discharge – 10µF or less, 30 volts or less. ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise specified) Parameter Intrinsic standoff ration (VB2B1 = 10V) (1) 2N2646 2N2647 Symbol Min Typ Max Unit η 0.56 0.68 - 0.75 0.82 - 4.7 7 9.1 0.1 - 0.9 - 3.5 - - 15 - Interbase resistance (VB2B1 = 3V, IE = 0) rBB Interbase resistance temperature coefficient (VB2B1 = 3V, IE = 0, TA = -55° to 125°C) αrBB Emitter saturation voltage (VB2B1 = 10V, IE = 50mA)(2) VEB1(sat) Modulated interbase current (VB2B1 = 10V, IE = 50mA) IB2(mod) Emitter reverse current (VB2E = 30V, IB1 = 0) Peak point emitter current (VB2B1 = 25V) Valley point current (VB2B1 = 20V, RB2 = 100ohms)(2) Base-one peak pulse voltage(3) kohms %/°C Volts mA 2N2646 2N2647 IEB2O - 0.005 0.005 12 0.2 µA 2N2646 2N2647 IP - 1 1 5 2 µA 2N2646 2N2647 IV 4 8 6 10 18 mA 2N2646 2N2647 VOB1 3 5 volts 6 7 Note 1: Intrinsic standoff voltage: η = VP-VF/VB2B1, where VP = peak point emitter voltage , VB2B1 = interbase voltage, VF = emitter to base one junction diode drop (≈ 0.45V @ 10µA). Note 2: PW ≈ 300µs, duty cycle ≤ 2% to avoid internal heating due to interbase modulation which may result i n erroneous readings Note 3: Base one peak pulse voltage is used to ensure minimum pulse amplitude for applications in SCR firing circuits and other types of pulse circuits. Rev. 20150306 High-reliability discrete products and engineering services since 1977 2N2646, 2N2647 SILICON UNIJUNCTION TRANSISTOR MECHANICAL CHARACTERISTICS Case TO-18 Marking Alpha-numeric Pin out See below Rev. 20150306