G E SOLID STATE eee aan 3875081 GE SOLID STATE Unijunction Transistors and Switches On vey 3875081 O018018 O1E 18018 D T 25-09 2N6027, 2N6028, GES6027, GES6028 Programmable Unijunction Transistor Features: Planar Passivated Structure 5 Low Leakage Current = Low Peak Point Current = Low Forward Voltage = Fast, High Energy Trigger Pulse Programmable yn = Programmable Reg = Programmable Ip Programmable ly = Low Cost TO-92 TO-98 The GE/RCA 2N6027, 2N6028 and GES6027, GES6028 PUTS are PNP three-terminal planar passivated devices available in the standard plastic TO-96 and TO-92 packages. The terminals are designated as anode, anode gate and cathode. The devices have been characterized as Programmable Uni- Junction Transistors (PUT), offering many advantages over conventional unijunction transistors. The designer can se- lect R, and Roto program unijunction characteristics such as 7, Reg; lp and ly to meet his particular needs. PUTs are specifically characterized for tong interval timers and other applications requiring low leakage and tow peak point current. PUTs similar types have been characterized for general use wheren the low peak point current of the 2N6028 and others is not essential. Applications of the PUT include timers, high gain phase control circuits and relaxa- tion oscillators. 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 unljunction transistor is replaced by the PUT plus resistors R, and Rp. Comparing the equivalent circuits of Figure 1(b) and 2(b), itis seen that both circuits have a diode connected to a voltage divider. When this diode becomes forward biased in the uni- 122 Applications: = SCR Trigger = Pulse and Timing Circuits = Oscillators = Sensing Circuits = Sweep Circults junction 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 Rz control the voltage at which the diode (anode to gate) becomes forward biased. After the diode conducts, the regeneration Inherent ina PNPN device causes the PUT to switch on. This generates a negative re- sistance characteristic from anode to cathode (Figure 2(b) simulating the modulation of A, for a conventional unijunc- tion. Resistors Ras and Ra, (Figure 1(a)) are generally unneces- sary when the PUT replaces a conventional UJT. This js illus- trated 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 re- turned directly to ground there is not current to bypass at the SCR gate. Resistor Raz is used for temperature compensa- tion and for limiting the dissipation In the UJT during capaci- tor discharge. Since R, (Figure 2) is not modulated, Rap can be absorbed into it. These types are supplied in JEDEG TO-92 package (GES6027, GES6028) and in JEDEC 10-98 package (2N6027, 2N6028). Devices in TO-98 package are supplied with and without seating flange (see Dimensional Outline). Fite Number 2050 oFGE SOLID STATE O1 veg 3675041, 00148019 3&8 [ 3875081 GE SOLID STATE B1E 18019 D Unijunction Transistors and Switches 2N6027, 2N6028, GES6027, GES6028 T 25-00% MAXIMUM RATINGS, Absolute-Maximum Values: GATE-GATHODE FORWARD VOLTAGE...,.... damn ea trace ren eenenees Dect e eee career et neeeeeaes +100V GATE-CATHODE REVERSE VOLTAGE* , ~100V GATE-ANODE REVERSE VOLTAGE .... + 100V ANODE-CATHODE VOLTAGE*.......... +100V DC ANODE CURRENT? (Note 1)... ccc cece eect e eet e eect ceeenseeetneees 150 mA PEAK ANODE, RECURRENT FORWARD (100s pulse width, 1% duty cycle) 20... cece eee eet t eee tet eben reeerenerereneeennas 1A (20us pulse width, 1% dutycycle)* ...... cee ne es cnet eenne 2A PEAK ANODE, NON-RECURRENT FORWARD a Ousec) 5A GATE CURRENT*. .... cs ccc n essence ere etaneresncenennes +20mA CAPACITIVE DISCHARGE ENERGY (Note 2).. 250pJd DISSIPATION (Total Average Power)(Note 1)...... 6.26. cece eee 300 mW OPERATING AMBIENT TEMPERATURE RANGE (Note 1)......... 00sec eeter veneers e ces eeen eens neeseces vee -50to +100C * In accordance with JEDEC registration data format. NOTES: 1. Derate currents and powers 1%/C above 25C. 2, E = 12CV2 capacitor discharge energy with no current limiting ELECTRICAL CHARACTERISTICS, At Ambient Temperature (Ta) = 25C Unless Otherwise Specified LIMITS CHARACTERISTICS SYMBOL 2N6027 2N6028 UNITS GES6027 GES6028 MIN. MAX. MIN. MAX Forward Voltage * (I; = S50mA) Ve - 1.5 - 1.5 Putse Output Voltage* Vo 6 - . 6 - Offset Voltage* (Vg = 10 V) Vy V Ra = Mo 0,2 1.6 0.2 1.6 Rg = 10ko 0.2 0.6 0.2 0.6 Peak Current* (Vg = 10 V) Ip Rg = 1Mo - 2 - 0.15 Re = 10ka - 5 - i Valley Current* (Vg = 10V) ly pA Re = 1M2 - 50 - 25 Rg = 10k2 , 70 - 25 - Rg = 20020 1.8 - 1 - mA Anode Gate-Anode Leakage Current (Vg = 40 V)* : T = 25C Igao - 10 - 10 T = 75C - 100 - 100 nA Gate to Cathode Leakage Current Vg = 40 V, Anode-cathode short leks - 100 - 100 - Pulse Voltage Rate of Rise t, - 80 - 80 ns *in accordance with JEDEC registration data format. 123G E SOLID STATE O1 vey 3875081 oOO01go20 4 Tr 3875081 G E SOLID STATE DIE 180206 BD Unijunction Transistors and Switches . T . 25 -O oS 2N6027, 2N6028, GES6027, GES6028 8. 0 oO? [FP] Veet IN] Re Rag th) tRe Ry Ry 78 FeRe On TE $2C$- 42329 Typleal circuit Unijunction transistor equivalent Negative resistance circuit characteristic (a) (b) {c) Fig, 1Unijunction transistor i R < Re < t ! i 9208-42330 Progr bleunijunction transistor Progr ble unijunction transi: Simplified, typical circuit, Fig. 1, a utilizing replacing unijunction transistor in typical equivalent circuit Programmable unijunction transistor, circuit, Fig. 1, a. (a) . () (c) Fig. 2 Programmable unijunction transistor equivalent of unijunction transistor. 124GE SOLID STATE 3875081 GE SOLID STATE O1E 18021 D Unijunction Transistors and Switches 2N6027, 2N6028, GES6027, GES6028 T'25-09 o ng Rte : Ro mw oR eRe + NL S* ay+Re > rob Ry va Tao s2cs-42331 Fig. 3 Offset voltage, peak current, and voltage current measurement circuits and waveform. Teks 2 Leao @ i. a * | ae 92cs- 42533 O%s-42332 i : Fig. 4 Anode gate-anode leakage current measurement circuit. Fig. 5Gate to cathode leakage current measurement circuit. +20V Yo 5 $ 1082 1652 evi-- ! { q 276 1 soz $%o oeVtoe | uF S200 tr t = 9209-42334 Fig. 6 Pulse output voltage and pulse voltage rate-of-rise measurement cireult and wavelorm, 125 O1 Dey 3475081 O0180e1 6b ITG E SOLID STATE 126 2N6027, 2N6028, GES6027, GES6028 608 Vity tT Tit, Tir try Tea TT} 1 IT TPH TTY PS Try 4 4 aL 2 a a GATE TO CATHODE ASSUMED SHORT a Ln. J ?F circuit ror : > a A > 1. PROGRAMMABLE UNIJUCTION iM 4 BE q H 8[- TRANSISTOR a 4 eK, 7 e aC _| rE 2 Se, & z - & ze A e Ps. O41 AA = Ney, oN a eae LY oq 3 E Pee, ~~ 3 & = | | = 2} PEAK CURRENT 4 Zoek ews o | 4 @ AS _A FUNCTION OF oor 02 7 Otgp SATE SOURCE [MPEDENCE = hue S 6L- PROGRAMMABLE UNIJUCTION 4 7 = a 4; TRANSISTOR aa a aL st tov aL 001 roll ol Los pay Oot | Pith tii) pit yd a it pe 0.01 2 ae 24 se 2 468, 2 46 Gao? 4 SB oo 4 E800 e001 4 * Bor" 4 oe 2 4 at 24 BaD 24 bao GATE SOURCE IMPEDENCE-kQ ,o. J, , GATE "ON-STATE CURRENT (Ig), Ig=Vg/ Rg mA 9208-42336 Fig. 7 Typical peak point current characteristics, Fig. 8 Typical valley current characteristics. e194, Lg PEAK POINT CURRENT (Ip )~ 4A VALLEY CURRENT (Tylo na =25 0 25 80 ozcs-azasr AMBIENT TEMPERATURE (1,)*C 9208-42338 a Fig. 9~ Typical peak point current characteristics. Fig. 10~ Typical valley current characteristics, 75 100 AMBIENT TEMPERATURE (Tal*C SIVOLTAGE SOURCE (Vs)*10 i Le 2 Z| Co < uw 8 aa = 5 <or 3 2 g < > 5 5 3 a | 5 nh 3 o I 8 _ 3S a 2 5 21000 98 Le RSE _ _ o| + | . 75 4 =-50 9-25 0 25 50 7 100 5 10 15 20 25 30 35 40 AMBIENT TEMPERATURE (Ta)-C VOLTAGE SOURCE {Vg]- sees-42340 92C8-42339 Fig. 11-- Typical offset voltage characteristics. Fig. 12 Typical pulse voltage characteristics. O1 Dey 3875081 0018022 4 I Unijunction Transistors and Switches : T Zz Ss ~ oFG E SOLID STATE O1 De J 3a7s081 o01a023 oO i 3875061 G E SOLID STATE O1E 18023 D Unijunction Transistors and Switches 2N6027, 2N6028, GES6027, GES6028 T'250% Here are four ways to use the PUT as a unijunction. Note the flexibility due to programmability. Applications from long time interval latching timers to wide range relaxation oscilla- tors are possible. IN4IS4 22ua 2nsi72 1 "Br 9205-42345 Br On 9209-42346 ' 92S-42347 e2c$-42344 Low ip; very high Iv, temperature and Low ip andiv Low fp; medium lv, temperature, Low ip, medium iv Vag compensation Vg compensation . Fig. 18Typical programmabk unijunction transistor circuits. START +28 This sampling circuit lowers the effective peak current of the output PUT, Q2. By aflowing the capacitor to charge with high gate voltage and periodically lowering gate voltage, when Q1 fires, the timing reistor 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 depen- dent. o Fig. 14Hour time-delay sampling circuit. 9209-42348 +15 Here is a handy circuit which operates as an oscillator anda L timer. The 2N6028 is normally on due to excess holding cur- 100kN Lema >220kn rent through the 100 kohm resistor. When the switch is mo- four = ene! j 7 mentarily closed, the 10 pF capacitor is charged to a full 15 (SE76FozFctoo) ~ volts and 2N6028 starts oscillating (1.8 Meg and 820 pF). The L circuit latches when 2N2926 zener breaks down again. wd ok | - os B20pF S220ka wirate| le p> j \ 7 wooo? Fig. 151-second, 1kHz oselilator circuit. 9208-42343 TERMINAL CONNECTIONS TO-92 and TO-98 Packages Lead 1 - Anode Lead 2 - Gate Lead 3 - Cathode 127