UNNJUNCTIONS, TRIGGERS AND SWITCHES Since the introduction of the commercial silicon unijunction transistor in 1956, General Electric has continued de- veloping an extensive fine of negative resistance threshold and four-layer switch devices. Each of these devices can be used as a power thyristor trigger, and each offers a special advantage for a particular trigger function. In addition, each can be used for various non-trigger applications. The featuresboth in design and characteristicswhich you receive with these products are concisely defined for each series: TYPES CONVENTIONAL UNIJUNCTIONS 2N489-494proved reliability; MIL spec version. 2N2646-47low cost, proved hermetic sealed device. PROGRAMMABLE UNIJUNCTION TRANSISTOR (PUT)variable threshold, low cost, fast switching speed, and circuit adjustable electrical characteristics. COMPLEMENTARY UNIJUNCTION TRANSISTORu!timate in temperature stability for timing and oscillator applications. SILICON UNILATERAL SWITCH (SUS)-a stable fixed low voltage threshold, low cost, high performance 4-layer diode. SILICON BILATERAL SWITCH (SBS)low voltage triac trigger, two silicon unilateral switches connected back to back. SILICON CONTROLLED SWITCH (SCS)high triggering sensitivity, 4-lead capability for multiple loads or dv/dt suppression. APPLICATIONS Unijunctions . Device Triggers Conventional Complementary Programmable 2N489-94, 2N2646 DSK1 2N6027 sus SBS 2N1671, 2N2160 2N2647 DSK2 2N6028 2N4983-90 2N4991-93 DC, Lo Cost F E E DC, Hi Perf. E DC, Volt Regulator F E E: E 1 E DC, Inverter DC, Hi AI/AT AC, @, Hi Perf. AC, , Hit AC, Lo RFI AC, , Lo Cost Trigger for SCRs nm >1 hr. F P F P F F P F P >1 min, Lo Cost F >1 min, Stable P <1 min, Lo Cost F <1 min, Stable P <10 P 10-25V E >25v P Stability F Cost F Adjust, Range E Military P Hi-Rel P F ajml al mi mim] ole] ol mae ain wlan] = F E F P F P E N N N F N N F F N N N Pp F E Economy rm E = Excellent, F Fair, P = Poor, N = Not Applicable With additional circuitry 2 Hermetic version 2N6116-18 123VUUAUUAUNAU 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 Transistors The General Electric 2N2646 and 2N2647 Silicon Unijunction Transistors have an entirely new structure resulting in lower saturation voltage, peak-point current and valley current as well as a much higher base- one peak pulse boltage. In addition, these devices are much faster switches. The 2N2646 is intended for general purpose industrial applications where circuit economy is of primary importance, and is ideal for use in firing circuits for Silicon Controlled Rectifiers and other applications where a guaranteed minimum pulse amplitude is required. The 2N2647 is intended for applications where a low emitter leakage current and a low peak point emitter current (trigger current) are required (i.e. long timing applications), and also for triggering high power SCRs. absolute maximum ratings: (25C) (uniess otherwise specified) Power Dissipation (Note 1) 300 mw RMS Emitter Current 50 ma Peak Emitter Current (Note 2) 2 amperes Emitter Reverse Voltage 30 volts Interbase Voltage 85 volts 65C to +125C 65C to +150C Operating Temperature Range Storage Temperature Range electrical characteristics: (25C) (unless otherwise specified) PARAMETER 2N2646 Min. Typ. Intrinsic Standoff Ratio (Vnz 10V) n 0.56 0.69 Interbase Resistance (Vas 3V, In = 0) Ruso 4.7 6.7 Emitter Saturation Voltage (Vas = 10V, I: = 50 ma) Viewsat 2 Modulated Interbase Current (Van = 10V, In = 50 ma) Ba(MOD) 24 Emitter Reverse Current (Vier = 30V, In = 0) EO 001 Peak Point Emitter Current (Vas = 25V) P 0.8 Valley Point Current (Van = 20V, Rue = 1002) I, 4 5 Base-One Peak Pulse Voltage (Note 3) Vom 3.0 8.5 SCR Firing Conditions (See Figure 26, back page) 1. Derate 3.0 MW/C increase in ambient temperature. The total power dissipation (available power to Emit- ter and Base-Two) must be limited by the external circuitry. . Capacitor dischargel0yfd or less, 30 volts or less. . The Base-One Peak Pulse Voitage is measured in the circuit below. This specification on the 2N2646 and 2N2647 is used to ensure a minimum pulse amplitude for applications in SCR firing circuits and other by the equation: Vr = 7 VoB + Vo we Ver = Interbase Voltage types of pulse circuits. 337 \ \ MOTE i: Max diameter leads af a gaging plane 054+ 001.000 below base seat to be within O07 of thei true location relative to max. widtn tab and to the max 230 diamater_measuced with a suitable gage. When gage is not used, measuie ment will be made at base seal MOTE 2: Lead diameter is controlled in the zone between 050 and 250 trom the hase seal Between 250 and end of lead a max of O21 1s held OTE 3: Calculated by measuring fange diameter, including lab and excluding. tab, and subtracting the sinailer diameter tsom the larger diameter APPROX WEIGHT 005 OZ ALL DIMENSIONS IN INCHES: Leapt az LEAD 4 2N2646,7 je 230 MAX 209 MIN 195 MAX 178 MIN 205 MAX 170 MIN 030 MAX | 7 10 ~ 3 LEADS O19 Max O16 MIN (NOTE 2} Pow THIS LEAD A GROUNDED \ To Housine cures ge < SERS bh NO ON. 2N2647 Max. Min. Typ. Max. 0.75 0.68 0.77 0.82 9.1 47 6.7 91 KO 2 volts 27 ma 12 -001 200) xa 5 1.0 2 Ba 8 9 18 ma 6.0 9.5 volts 4. The intrinsic standoff ratio, 7, is essentially constant with temperature and interbase voltage. 7 is defined Where Vp = Peak Point Emitter Voltage Vp = Junetion Diode Drop (Approx. .5V)Ta= 125C = 25C Ta Ta= -55 2N2646, 7 STATIC EMITTER CHARACTERISTICS Tas +125C Vee <30V EMITTER VOLTAGE - Ve - VOLTS 6 8 4 16 EMITTER CURRENT ~I_-MILLIAMPERES FIGURE 4 STATIC EMITTER CHARACTERISTICS Tat + 25C EMITTER VOLTAGE -V_-VOLTS Vpat!OV Vaa* 5V 10 2 14 EMITTER CURRENT Ie ~ MILLIAMPERES. FIGURE 7 STATIC EMITTI CHARACTERISTICS Ta = 755C Vpn* 204 Naw *20V pp tlov EMITTER VOLTAGE~V_ -VOLTS 2 4 6 8 19 2 4 16 EMITTER CURRENT -Ie~MILLIAMPERES FIGURE 10 INTERBASE VOLTAGE - Vag" VOL INTERBASE VOLTAGE -Vgg- VOLTS INTERBASE VOLTAGE ~- Vgg VOLTS /1g20MA Ig*30MA STATIC INTERBASE CHARACTERISTICS Tas +125C 4 6 a 10 12 14 16 18 20 BASE TWO CURRENT - I. MILLIAMPERES FIGURE 5 30MA Tex 40MA SOMA STATIC INTERBASE CHARACTERISTICS Tyet 25C 4 6 BASE TWO CURRENT -IgzMILLIAMPERES FIGURE & STATIC INTERBASE CHARACTERISTICS Ta = 758C Tes!OMA/ 3, =20MA I_gs30MA Tes 40MA 4 6 8 F 14 BASE TWO CURRENT ~Igg- MILLIAMPERES FIGURE 11 338 PEAK POINT CURRENT-Ip-MICROAMPERS PEAK POINT CURRENT -Ip-MICROAMPERES PEAK POINT CURRENTIp-MICROAMPERES GOTH PERCENTILE MEDIAN Tet +125C 2 34 6 8 0 20 30 INTERBASE VOLTAGE - FIGURE 6 PECENTILE MEDIAN Tar +25C 2 3 4 6 8 0 20 30 INTERBASE VOLTAGE Vgg" VOLTS FIGURE 9 SOTH PERCENTILE MEDIAN Ty #-85C 2 34 6 8 10 2 3% INTERBASE VOLTAGE -Vgg-VOLTS FIGURE 12 40NORMALIZED PARAMETER: 9OTH PERCENTILE MAX 2N2647 MEDIAN PERCENTILE MEDIAN is ] . | | S | [ h NORMALIZED Ta, (moo) VS TEMP as SS a NORMALIZED Veq,(SAT) VS TEMP 10 T oo _ PS Rae ee a6 J a9 480: OO RRO eae +60. ABO. AMBIENT: TEMPERATURE -%y ~DEGREES CEN TIGNADE FIGURE 16 HIDE os 339 pT Repo 2 4.7K \ 4 x | Repo: 6.5K L N | Troost 9.1K | INTERBASE CHARACTERISTICS AT ANY AMBIENT TEMPERATURE MAY BE DETERMINEO BY DIVIDING THE HORIZONTAL SCALE BY Kp FROM FIGURE 18 NORMALIZED Tg, (MOD} VS Veg Te=50MA Tas 25C NORMALIZED Ve (SAT) VS Vagee 2N2646, 7 16 14 3" 4 @ a 3 2 ie 2 2 z $s 3 w 5 3 2 0 z e x 1 Bg # I r & z 3 5 el . 6 wy 08 z < 3S ao & > 4 a 5 5g 0.6 Z 7 > 2 z S z oO 10 iS -60 -40 ~20 Oo +20 +40 +60 +80 +100 +120 +140 INTERBASE VOLTAGE -Vgg VOLTS AMBIENT TEMPERATURE - Ta ~ DEGREES CENTIGRADE FIGURE 20 FIGURE 21 8 3 5 3 u g 2 g = t 5 = 3 3 y wl 2 8 & E 4 5 Z z : 8 4 = 2 5 $ a u a 3 a u : : 0.001 O01 On 1 10 az o4 06 08 10 Le 4 16 is 2.0 TRIGGER PULSE WIDTH-MICROSECONDS CAPACITANCE - C1 - MICROFARADS MINIMUM TRIGGER AMPLITUDE AS A FUNCTION OF TRIGGER PULSE WIDTH FOR TURN ON OF UNWUNCTION TRANSISTOR 20 2.2 20 18 @ qs 2 '* g > w 16 wo % Bis 3 3 z14 zie x x ib ii : Woe Lo w g 5 10 7 os y w a 3 < 08 0s 2 a N06 3 oa z z zZ04 z S oz 2 2 Oz 9001 9002 0005 ool 002 0050 02 os i 2 8 0 5 10 18 20 28 30 35 40 CAPACITANCE ~ C\-MICROFARADS INTERBASE VOLTAGE Vgg" VOLTS FIGURE 24 FIGURE 25 MINIMUM SUPPLY VOLTAGE - Vv; VOLTS MINIMUM SUPPLY VOLTAGE 7, - VOLTS 3 6 - B 05 O41 0.5 ( 5 Io CAPACITAMCE C7 MICROFARADS Ol 0.1 ' lo CAPACITANCE C, MICROFARADS FIGURE 26A-Both types- Lo &mMed. SCR's FIGURE 268-2N2647-Hi Current SCR's 340