<£zmL-£anauatoi ZPiaauati, 20 STERN AVE. SPRINGFIELD, NEW JERSEY 07081 TELEPHONE: (973) 378-2022 (212) 227-8008 FAX: (973)378-8980 USA 2N4948 2N4949 Silicon annular unijunction transistors MAXIMUM RATINGS (TA = 25°C unless otherwise noted) Rating (TO-18Excwt L**d Petition) Value Unit 360* mW 50 mA 1.0** Amp 30 Volts -65 to +200 •c Symbol RMS Power Dissipation* PD RMS Emitter Current 'e Peak Pulse Emitter Current** *e Emitter Reverse Voltage VB2E T Storage Temperature Range stg * Derate 2.4 mW/°C increase in ambient temperature. Total power dissipation (available power to Emitter and Base-Two) must be limited by external circuitry. Interbase voltage (Vjj2Bl) limited bY power dissipation, 'B2B1 PD" ** Capacitance discharge current must fall to 0.37 Amp within 3. 0 ms and PRR S 10 PPS. ELECTRICAL CHARACTERISTICS (T» = 25-Cunl«s otherwise noted) Characteristic Intrinsic Standoff Ratio (V = 10 V) Note 1 B2B1 Interbase Resistance (V B2B1 = 3 '° V - 'E = 0) Symbol 2N4948. 2N4949 Interbase Resistance Temperature Coefficient (V B2B1 = 3 '° v - 'E l0 ' TA = "a5'C '° •10°'C> Emitter Saturation Voltage (V B2B1 ' '° V > 'E ' 5° mAI Note 2 Modulated Interbase Current <V B2B1 = 1 0 V ' ' E = 5 0 m A ) Emitter Reverse Current (V B2E = 30 V 'fll - 0) (V B2E '3° V ' 'B! = °' TA = 125°C) Peak Point Emitter Current (V - 25 V) 2N4948 b" 2N4949 Valley Point Current (V B2B1 ""•2° V l R B2 " '°° Ohms| Note 2 2N4948. 2N4949 Base-One Peak Pulse Voltage (Note 3. Figure 3) Maximum Oscillation Frequency (Figure 4) 1 2N4948 2N4949 2N4949 2N4948 R BB " R RR V EBl(sat) 'B2(mod) 'EB20 Min Typ Max 0.55 0.74 - 0.82 0.86 4.0 7.0 12.0 0. 1 - 0.9 - 2.5 3.0 12 15 - - k ohms •;:/-c Volts mA - S.O 10 nA - - 1.0 I»A _ - 0.6 0.6 2.0 1.0 2.0 4.0 - 3.0 6.0 5.0 8.0 - - 1.25 - [ 'v v OBI (ma.x) Unit MA mA Volt? MHz N.I Semi-Conductors reserves the right to change test conditions, parameter limit!; and packuge dimensions without notice Inlbrmiuion 1'umished by NJ Somi-Cunductors is believed to be both accurate and reliable at the lime of going to press. However VI Semi-Conductors assumes no responsibility for any errors or omissions discovered in its use. NJ .SeMii-Conductors encourages tustnucrs to verify Ih.U dutrchcels are current hetbre placing orders NOTES 1 intrinsic standoff ratio n is defined by equation : 2, Use pulse techniques: PW 300 /is duty cycle 2% to avoid internal heating due to mterba: e modulation which may result in erroneous readings. Where V, - Peak Point Emitter Voltage VHH interbase Voltage Emitter to Base One Junction Diode Drop 3. Base>One Peak Pulse Voltage is measured in circuit of Figure 3 This specification is used to ensure minimum pulse amplitude tor applications in SCR firing circuits and other tyoes of pulse Circuits ( 0.5 V @ 10 iiA) FIGUIE 1-UNIJUNCTION TMNSISTOI SYMBOL AND NOMENCLATURE FIGURE 2 - STATIC EMITTER CHARACTERISTICS CURVES <Lu||ented to She* Dclnlsl Vni, FIGURE 3 -¥ o>1 TEST CIRCUIT a»p,Mi fw.,«,M OK.II.W.I FIGURE 4 - F(mal) MAXIMUM FREQUENCY TEST CIRCUIT