2N4870, 2N4871 SILICON CONTROLLED RECTIFIERS High-reliability discrete products and engineering services since 1977 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 RMS power dissipation(1) RMS emitter current Peak pulse emitter current (2) Symbol Value Unit PD 300 mW Ie 50 mA ie 1.5 Amp Emitter reverse voltage VB2E 30 Volts Interbase voltage † VB2B1 35 Volts Operating junction temperature range TJ -55 to 125 °C Storage temperature range Tstg -55 to 150 °C Note 1: Derate 3.04mW/°C increase in ambient temperature. Note 2: Duty cycle ≤ 1%. PRR = 10PPS. A = 25°C. ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise specified) Characteristic Intrinsic standoff ratio (VB2B1 = 10V)(1) 2N4870 2N4871 Symbol Min Typ Max Unit η 0.56 0.70 - 0.75 0.85 - 4.0 6.0 9.1 0.1 - 0.9 - 2.5 - - 15 - - 0.005 1.0 - 1.0 5.0 Interbase resistance (VB2B1 = 3.0V, IE = 0) RBB Interbase resistance temperature coefficient (VB2B1 = 3.0v, IE = 0, TA = -65° 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) IEB20 Peak point emitter current (VB2B1 = 25V) Valley point current (VB2B1 = 20V, RB2 = 100ohms)(2) IP kohms %/°C Volts mA µA µA 2N4870 2N4871 IV 2.0 4.0 5.0 7.0 - mA 2N4870 2N4871 VOB1 3.0 5.0 6.0 8.0 - Volts Base-one peak pulse voltage Note 1: Intrinsic standoff ration: VP = η VB2B1+ VF, where VF is about 0.49V at 25°C @ IF = 10µA and decreases with temperature at about 2.5mV/°C. Components R1, C1, and the UJT form a relaxation oscillator; the remaining circuitry serves as a peak –voltage detector. The forward drop of diode D1 compensates for VR. To use, the “cal” button is pushed and R3 is adjusted to make the current meter, M1, read full scale. When the “cal” button is released, the value of η is read directly from the meter, if full scale on the meter reads 1.0. Note 2: Use pulse techniques: PW ≈ 300µs duty cycle ≤ 2% to avoid internal heating due to interbase modulation which may result in erroneous readings. Rev. 20120705 High-reliability discrete products and engineering services since 1977 2N4870, 2N4871 SILICON CONTROLLED RECTIFIERS MECHANICAL CHARACTERISTICS Case: TO-92 Marking: Body painted, alpha-numeric Pin out: See below Rev. 20120705 High-reliability discrete products and engineering services since 1977 2N4870, 2N4871 SILICON CONTROLLED RECTIFIERS Rev. 20120705 High-reliability discrete products and engineering services since 1977 2N4870, 2N4871 SILICON CONTROLLED RECTIFIERS Rev. 20120705 High-reliability discrete products and engineering services since 1977 2N4870, 2N4871 SILICON CONTROLLED RECTIFIERS Rev. 20120705