G E SOLID STATE on vef}sazsoa1 corsoou n 38750871 G E SOLID STATE O1E 18004 D Unijunction Transistors and Switches T . 3 7 . 2 | 2N4870, 2N4871, GET4870, GET4871 Silicon Unijunction Transistors 10-92 TO-18 The GE/RCA 2N4870, 2N4871, and GET4870, GET4871 are _ circuits, relaxation oscillators and other typical unijunction unijunction silicon transistors intended for general-purpose _transistor applications. These unljunction transistors are industrial applications where circuit economy is of primary supplied in JEDEC T0-92 package (2N4870, 2N4871) and in importance. The 2N4870, 1 and GET4870, 1 areidealforuse JEDEC TO-18 package (GET4870, GET4871). in firing circuits for silicon controlled rectifiers, timing MAXIMUM RATINGS, Absolute-Maximum Values: EMITTER REVERSE VOLTAGE 0.0... 0. cece ec ce eee er ne cee ee nent e eee e ne cece eee eer et bee ees b cee nese bbb etens 30V INTERBASE VOLTAGE RMS EMITTER CURRENT............0cc ees e cece een eee PEAK EMITTER CURRANT (Note 1) POWER DISSIPATION (Note 2)... 62... cece cece een ree tree n eee eee een eee Cen eb e ee Eset tee tebetbeepaeaeseneenas OPERATING TEMPERATURE RANGE . ~65 to + 125C STORAGE TEMPERATURE RANGE. ........ 0000s ccc scree scenes eee eer ten tener ree teneensereeeseseugeeuteres 65 to + 160C NOTES: 1. Duty cycle < 1% PRR = 10PPS. 2. Derate 3 mW/C increase In ambient temperature. The total power dissipation (available power to Emitter and Base-Two) must be limited by the external circuitry. EMITTER 4 VOLTAGE a2 +20V +0.5 E O curorrple RESISTANCE ele- SATURATION REGION REGION | REGION \ Ve IINT PEAKPOINT I _, Bz | 5 EMITTER-T0-BASE VeB +e 1 NeetOV | GNesDlooE I CHARACTERISTI a You i ! Ve I 1 VALLEY POINT Ve (20) 4)4 Hoe = = 21% wr To ' EMITTER Oo - | Tegt0 ' 1 CURRENT 928-42000 = 92cs-42369 L iv sows ' Fig. 1~Unijunction transistorsymbol Fig. 2Typicalbase-1 peak-pulse $28-a2401 &nd nomenclature used for voltage circuit, Eo current and voltage circuit. Fig. 3-Static emitter characteristics waveforms, File Number 1949 108 G E SOLID STATE O14 ve Bsa7soai 00148005 4 i . 3875081 GE SOLID STATE OTE 18005 D Unijunction Transistors and Switches 2N4870, 2N4871, GET4870, GET4871 T*37-2/ ELECTRICAL CHARACTERISTICS, At Ambient Temperature (Ta) = 25C Unless Otherwise Specified LIMITS CHARACTERISTICS SYMBOL 2N4870 2N4871 UNITS MIN. TYP. MAX, MIN. TYP. MAX Intrinsic Standoff Ratio (Veg = 10 V)(Note 1) n 0.56 - 0.75 0.7 - 0.85 - Interbase Resistance (Veg = 3V, Ie = 0) R, 4 6 9.1 4 6 9.1 kQ Emitter Saturation Voltage (Vgp = 10 V, Ie = 50 mA) Ve(sat) _ 2.5 _ - 2.5 - Vv Modulated Interbase Current (Veg = 10V, Jp = 50mMA | Ipo(mod) - 2.2 _ ~ 2.7 - mA Emitter Reverse Current (Vg2 = 90V, tg; = 0) leo - 0.05 1 - 0.05 1 BA Peak Point Emitter Current (Vpp = 25 V) Ip = 1 5 - 1 Valley Point Current (Vp = 20V, Rigo = 1009) ly 2 5 - 4 7 _ mA Base-Ono Peak Pulse Voltage (Note 2)(Fig. 2) Vos 3 6 - 5 8 - Vv NOTES: 1. The intrinsic standoff ratio, n, is essentially constant with temperature and interbase voltage. n\s defined by the equation: Vp = Vag + Vp Where Vp = Peat Point Emitter Voltage Vea = Interbase Voltage Vp = Junction diode Drop (Approx. 0.5 V) Nn . The Base-1 Peak Pulse Vottage is measured in the circuit below. This specification is used to ensure a minimum pulse amplitude for applications in SCA firing circuits and other types of pulse circuits. Veg" 20V Veg"tov Ves"SV Tee EMITTER-TO-BASE VOLTAGE ( Veg)-V INTERBASE SUPPLY VOLTAGE (Vgp)V 16 18 6 14 0 6 12 14 16 16 20 EMITTER CURRENT (Te)mA BASE 2 CTpal- MA os 4208 #265-42503 Fig. 4 Typical static emitter characteristics. Fig. 5 Typical static interbase characteristics. AMBIENT PEAK POINT CURRENT (Ipi ma VALLEY POINT CURRENT ( on 2 4 8 410 15 20 25 30 as BASE SUPPLY VOLTAGE (Vpq ey INTERBASE SUPPLY VOLTAGE ( Vgg)V e2cs~42508 #20S-42309 Fig. 6 Typical peak point current characteristic. Fig. 7 Typical valfey point current characteristio. 109 G E SOLID STATE 01 ve ff sa7s50a1 001a800b O i 3875081 GE SOLID STATE O1E 18006 D Unijunction Transistors and Switches T 37-2 l 2N4870, 2N4871, GET4870, GET4871 SUPPLY VOLTAGE EMITTER CURRENT (Ie NORMALIZED INTERBASE RESISTANCE O4 75 = -50 25 sO 67S JUNCTION TEMPERATION (Ty)*C 9268-42310 Fig. 8 Normalized interbase resistance characteristic. TERMINAL CONNECTIONS TERMINAL CONNECTIONS TO-92 TO-18 Lead 1 - Emitter Lead 1 - Emitter Lead 2 - Base 1 Lead 2- Base 1 Lead 3 - Base 2 Lead 4 - Base 2 110