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 123PROGRAMMABLE UNIJUNCTIONS (PUT D13T SERIES) The 2N6028 is specifically characterized for long interval timers and other applications requiring low leakage and low peak point current. The 2N6027 has been characterized for general use where the low peak point current of the 2N6028 is not essential. Applications: SCR Trigger Sensing Circuits @ Pulse & Timing Circuits Sweep Circuits Oscillators Outstanding Features of the PUT: Low Cost Programmable Low Leakage Current Programmable Rez Low Peak Point Current Programmable |, Low Forward Voltage Programmable |, Fast, High Energy Trigger Pulse Planar Passivated Structure Peak Gate to Anode Pk. Point Current Iv Anode Current Max. Valley Reverse 20 psec. Current Cc. @Re = Min. JEDEC . . . 1Meg. @ Re = 10k Min. . Types ) (uA) (uA) . Package | 2N6027 2NG028 COMPLEMENTARY UNIJUNCTIONS (D5K SERIES) The D5K offers the ultimate in unijunction stability and uniformity. Low frequency oscillators and timers can be built using the D5K with better than 1.0% accuracy over extended temperature ranges. The DSK has characteristics like those of a standard unijunction except the currents and voltages applied to it are of opposite polarity than those of the standard devices. te leo Vo Rto v Peak Point Emitter Peak Operating Frequency Interbase n Valley Emitter Reverse Pulse . Stability Resistance Intrinsic Current Current Current Voltage from 25C GE @ in, em Standoff Min. . Max. Min. T s5S to + 150C fo Type Ratio (mA) (nA) W) Package 125 PUVLULUAUAULAAASilicon |_2N5810-6017 SERIES SEE GES5810-6017 | Programmable Sc Unijunction Dist SERIES Transistor 2N6027,8 (PUT) . The General Electric PUT is a three-terminal planar passivated PNPN device in the standard plastic low cost TO-98 package. The terminals are designated as anode, anode gate and cathode. The 2N6027 and 2N6028 have been characterized as Programmable Unijunction Transistors (PUT), offering many advantages over conventional unijunction transistors. The designer can select R,; and R2 to program unijunction characteristics such as n, Rpp, Ip and Iy to meet his particular needs. The 2N6028 is specifically characterized for long interval timers and other applications requiring low leakage and low peak point current. The 2N6027 has been characterized for general use where the low peak point current of the 2N6028 is not essential. Applications of the 2N6027 include timers, high gain phase control circuits and relaxation oscillators. \ 7 fy A ity anand 10 Outstanding Features of the PUT: Applications: 1. Planar Passivated Structure @ SCR Trigger C : 2. Low Leakage Current @ Pulse and 3. Low Peak Point Current Timing Circuits SYMBOL 4. Low Forward Voltage Oscillators 5. Fast, High Energy Trigger Pulse @ Sensing Circuits 6. Programmable 7 Sweep Circuits 7. Programmable Rgg L 8. Programmable Ip - ; 9. Programmable Iv NOTE |: LEAD DIAMETER 1S CONTROLLED IN THE 10. Low Cost PLANE, GETWCEN 250 AND END OF LEAD A MAX, OF .OZI IS HELD. Operation of the PUT as a unijunction is easily understood. Figure 1(a) shows a basic unijunction circuit. Figure 2(a) shows identically the same circuit except that the unijunction transistor is replaced by the PUT plus resistors R; and R2. Comparing the equivalent circuits of Figure 1(b) and 2(b), it is seen that both circuits have a diode connected to a voltage divider. When this diode becomes forward biased in the unijunction transistor, R; becomes strongly modulated to a lower resistance value. This generates a negative resistance characteristic between the emitter E and base one (B,). For the PUT, the resistors R; and R2 control the voltage at which the diode (anode to gate) becomes forward biased. After the diode conducts, the regeneration inherent in a PNPN device causes the PUT to switch on. This generates a negative resistance characteristic from anode to cathode (Figure 2(b)) simulating the modulation of R, for a conventional unijunction. Resistors Rpz and Rp, (Figure 1(a)) are generally unnecessary when the PUT replaces a conventional UST. This is illustrated in Figure 2(c). Resistor Rg, is often used to bypass the interbase current of the unijunction which would otherwise trigger the SCR. Since R, in the case of the PUT, can be returned directly to ground there is not current to bypass at the SCR gate. Resistor Ryo is used for temperature compensation and for limiting the dissipation in the UJT during capacitor discharge. Since Rz (Figure 2) is not modulated, Rg can be absorbed into it. vy, em + Cea N 1(a) Typical Circuit 1b) UJT 1(c) Negative 2(a) PUT Replacing 2(b) UJT 2(c) Simplified Typical Equivalent Resistance UJT in Typical Equivalent Cireuit 1(a) Circuit Characteristic Circuit 1(a) Circuit Using PUT Figure 1 Unijunction Transistor Figure 2 PUT Equivalent of UJT 510D13T SERIES R 3 A 2N6027, 8 absolute maximum ratings: (25C) & Voltage Ri *Gate-Cathode Forward Voltage +40 V *Gate-Cathode Reverse Voltage -5V *Gate-Anode Reverse Voltage +40 V *Anode-Cathode Voltage +40 V Current *DC Anode Currentt 150 mA Peak Anode, Recurrent Forward (100 usec pulse width, 1% duty cycle) 1A *(20 psec pulse width, 1% duty cycle) 2A Peak Anode, Non-recurrent Forward (10 psec) 5A *Gate Current +20 mA Capacitive Discharge Energy++ 250 pI Power *Total Average Powert 300 mW Temperature *Operating Ambientt Temperature Range 50C to +100C +Derate currents and powers 1%/C above 25C I ; TtE = % CV? capacitor discharge energy with no cutrent limiting GAO Figure 3 electrical characteristics: (25C) (unless otherwise specified) 2N6027 2N6028 (D13T1) (D13T2) Fig. No. Min. Max. Min. Max. *Peak Current (V, = 10 Volts) Ip 3 (Rg = 1 Meg) 2 15 pA (Rg = 10 k) 5 1.0 pA *Offset Voltage (V, = 10 Voits) Vr 3 (Rg = 1 Meg) 2 16 2 6 Volts (Rg = 10k) 2 6 2 .6 Volts Figure 4 *Valley Current (V, = 10 Volts) Iy 3 (Rg = 1 Meg) 50 25 pA (Rg = 10k) 70 25 pA (Rg = 200 2) 1.5 1.0 mA Anode Gate-Anode Leakage Current *(V, = 40 Volts, T = 25C) Icao 4 10 10 nA (T = 75C) 100 100 nA Gate to Cathode Leakage Current (V, = 40 Volts, Anode-cathode short) Igxg 5 100 100 nA *Forward Voltage (I- = 50 mA) VF 1.5 1.5 Volts *Pulse Output Voltage Vo 6 6 6 Volts Pulse Voltage Rate of Rise t, 6 80 80 nsecs. Figure 5 *JEDEC registered data Figure 6 511to - PEAK POINT CURRENT In wiCROAMPS D13T SERIES 2N6027, 8 PEAK CURRENT AS A FUNCTION OF GATE SOURCE IMPEDENCE FOR 13 T TYPE PROGRAMMABLE UNIJUNCTION TRANSISTOR Vez IOV 1 Q.! 10 10 100 SPEC 2N6027 SPEC MAX 2N6028 1000 GATE SOURCE IMPEDENCE IN OHMS (IN THOUSANDS) Ip- PEAK POINT CURRENT- MICROAMPS 0.01 Ip vs Gate Source Impedance Vg #10 VOLTS Rg*lOk Rig# 100k Rgt | MEG 75 -50 -26 26 50 75 100 AMBIENT TEMPERATURE-*C |, vs Temperature and Rg 3 Rg* 2 \' MEG = g2 w 2 Vg = 10 VOLTS 4 > R \ G* PL EN ey 7 NY NY > Rg*lOk ~ S44 ors ~50 -25 25 50 75 100 AMBIENT: TEMPERATURE-C Vy vs Temperature and Rg 10,9000 512 MILLIAMPS NT- EY CURRE' Ily- VALLEY O.t 001 00 1000 100 ly-VALLEY CURRENT-MICROAMPS 3 O01 VALLEY CURRENT AS A FUNCTION OF GATE "ON STATE" CURRENT GATE TO CATHODE ASSUMED SHORT CIRCUIT FOR PROGRAMMABLE UNIJUNCTION MIN 2N6028 Ol Oo Ig = Vg/RgiMiLLiAMes) l, vs Gate on state Current Vg" 10 VOLTS * 10k Rg = 100k Rg 1 MEG -75 -50 -25 25 80 78 100 AMBIENT TEMPERATURE-C l, vs Temperature and Rg 30 | | vv fi g 510k zI6k > rae 2 S27k L z= a $ be Fo > & 1 C =0.2 MICROFARADS 3 w ld 3 _ a a a C= (000 PICOFARADS | O5 10 20 30 40 V-VOLTAGE -VOLTS Peak Output Voltage 100APPLICATIONS TYPICAL UNIJUNCTION CIRCUIT CONFIGURATIONS Here are four ways to use the PUT as a unijunction. Note the flexibility due to programmability. Appli- cations from long time interval latching timers to wide range relaxation oscillators are possible. HOUR TIME DELAY SAMPLING CIRCUIT This sampling circuit lowers the effective peak cur- rent of the output PUT, Q2. By allowing the capacitor to charge with high gate voltage and periodically lowering gat voltage, when Q] fires, the timing resistor can be a value which supplies a much lower current than Ip. The triggering requirement here is that minimum charge to trigger flow through the timing resistor during the period of the Q1 oscillator. This is not capacitor size dependent, only capacitor leakage and stability dependent. 1 SECOND, 1kHz OSCILLATOR Here is a handy circuit which operates as an oscillator and a timer. The 2N6028 is normally on due to excess holding current through the 100 kohm resis- tor. When the switch is momentarily closed, the 10 uF capacitor is charged to a full 15 volts and 2N6028 starts oscillating (1.8 Meg and 820 pF). The circuit latches when 2N2926 zener breaks down again. D13T SERIES 2N6027, 8 : 8, "Bo" $ 2 MEG b j "Ee a 21.8 MEG G Pur PUT 2N5172 t $ 2MEG f S100k 228 5 = MEG 8, LOW Ip I VERY HIGH Ly LOW Ip, LOW Ty TEMPERATURE AND Veg COMPENSATION "Bo" "Bo" S1.8k I "E" INGISA ; "Et SEBR NYN4I54 PUT | MEG PUT - 2 > , $2.7 | 2 32.7k Sueg 327k a Ty B; B," LOW Ip, MEDIUM ly LOW Ip, MEDIUM Ly TEMPERATURE COMPENSATION VAG START +28V oo" 210M 5 , 315K = 3 1000M iM im a2 wv AWA 7 200 3 C pNzneoe > 2N6028 & 30K INa443 PULSE 5uF > 7 Ge7aro1s-565) T ] Pspr $100 OUTPUT | C (GE74FOIB-505) ~ [OpF GE76FO2FCI00 INITIATE +15 Zz 2 2 100k $1.8 MEG $220k 3 4 : T 2N2926 | 2N6028 - > $220k m 3 per 513