VUUAUUAUNAU UATE CONVENTIONAL UNISUNCTIONS General Electric produces a very broad line of standard UJTs. The TO-5 ceramic disc bar structure device has been the workhorse of the unijunction industry for over 10 years. MIL versions are available on the 2N489-494 series. The cube structure TO-18 series offers excellent value for those requiring proved, low cost units. Applications Oscillators SCR Triggers Timers Frequency Divider Sawtooth Generators Stable Voltage Sensing Rno te leo Vos, interbase n \Wv Peak Point Emitter Base One Resistance intrinsic Valley Emitter Reverse Current Peak Pulse = 3V Standoff Current Current Voltage GE le = 0 Ratio Min. Max, Max. T2=25C Min. Comments Type @ Vos = 10V (mA) (uA) (uA) 7) Package 2N489 2N489/ * i -51-.62 2N4690 2N490 2N490A * 2N49068 2N4906 2N491 2N4914 * 2N4916 2N492 2N492A\ * 2N492B 2N4926 2N493 2N493/A * 2N493B 2N494 2N494A * 2N494B 2N494C 2N1671 2N1671A 2N1671B 2n1671C 2N2160 2N2646 .56-.75 10-5 Bar Structure 10-18 Cube Structure 2N2840 -62 Typical * JAN & JANTX types available 2 Vee=1.5V 124Silicon Unijunction Transistor Pr P= Pr 2N2840 | 2N2906-7 SEE GES2906-7 | The General Electric Type 2N2840 Silicon Unijunction transistor maintains its negative resistance region for extremely low interbase voltages. This transistor is specifically characterized for use at interbase voltages less than 10 volts and as low as 1.5 volts. The transistor is hermetically sealed in a welded case equivalent to the TO-18, except for lead orientation. Base-two is electrically common to case. absolute maximum ratings: (25C) Power Dissipation* 300 RMS Emitter Current 50 Peak Emitter Current** 2 Emitter Reverse Voltage 30 Interbase Voltage 85 Operating Temperature Range 65 to +150 Storage Temperature Range -65 to +175 *Derate 2.4 mw/C increase in ambient temperature. Maximum power available to the transistor must be limited by external circuitry to be within this rating. **Capacitor Discharge10 ufd or less, 30 volts or less. electrical characteristics: (25C) PARAMETER Emitter Peak Point Voltage (Vse = 1.50V) Emitter Peak Point Current (Ves = 1.50V) Intrinsic Standoff Ratio (Ves = 10V) *** Emitter Valley Point Voltage (Ves = 1.50V) Emitter Valley Point Current (Vas = 1.50V) Emitter Base Saturation Current (Vss = 1.50V; Ves: = 1.50V) Emitter Reverse Current (Vax = 30V; In: =: 0) Interbase Resistance (Ves = 1.50V; In = 0) ***y is defined by the equation Vp = 7 Vas + Vp where Vp ~ .5V. Teisat) Te 348 230 MAX [ (209 MIN MOTE i: Max. diameter feads at a gaging plane 054-+.001000 betow base seat t Pe man om to be within 007 of their true location relative to max. width tab and te the max TT .230 diameter measured with a suitable gage. When gage is not used, measure ment will be made at base seat. WOTE 2: Lead diameter is controtled in the zone between 050 and 250 from the base seat. Between .250 and end of ead a max. of 021 is held. wore 3: Calculated by measuring flange diameter, including tab and excluding tab, and subtracting the smaller diameter from the larger diameter, APPROX WEIGHT O15 OZ ALL DIMENSIONS IN INCHES LEAO | B2 LEAD 4 THIS LEAD GROUNDED TO HOUSING 8 a EMITTER... E + WV 4, BE Mio. 8 \O B2 > \ 046 MAX O32 MIN oremin (NOTE 3) Min. Typ. Max. 1.30 1.4 1.50 volts 7.5 10 ya 62 95 1.10 volts 20 40 70 ma 20 40 ma -05 1 ya 4.7 7 91 Ke TEMPERATURE COEFFICIENT, MV/C 10% MED 90% Vp -2.8 ~3.4 -4.0 Ve 17 72.0 |.7-2.4EMITTER PEAK VOLTAGE Vp- VOLTS EMITTER VALLEY VOLTAGE -Vy- VOLTS -40 -20 20 20 2.2 LL NORMALIZED INTERBASE RESISTANCE (Kp) 7 08 O6 o 60-40 40 60 TEMPERATURE -C 40 60 TEMPERATURE - C 80 80 -20 +20 +40 YUNCTION TEMPERATURE-T,~- DEGREES CENTIGRADE Vpp*3V Vga 't.5V loo 100 120 120 140 140 +60 160 160 +80 +100 EMITTER PEAK CURRENT -Ip- pA EMITTER VALLEY CURRENT Iy-MA 349 +120 -60 +140 -40 +160 = +180 20 40 60 ao AMBIENT TEMPERATURE ~T, ~C 20 40 60 TEMPERATURE - C 80 2N2840 00 Vga" |.5V 120 120 40 140 \60 160