Unijunction Transistors (UFT)
| Part | RoHS | Manufacturer | Configuration | Surface Mount | Maximum Power Dissipation (Abs) | Package Body Material | Transistor Application | Maximum Emitter Current | Terminal Form | Package Shape | No. of Elements | Maximum Inter-base Voltage | No. of Terminals | Package Style (Meter) | Sub-Category | Maximum Operating Temperature | Transistor Element Material | Minimum Operating Temperature | Terminal Finish | Minimum Intrinsic Stand-off Ratio | Maximum Static Inter-Base Resistance | Terminal Position | JESD-30 Code | Case Connection | Qualification | Maximum Intrinsic Stand-off Ratio | Minimum Static Inter-Base Resistance | JEDEC-95 Code | JESD-609 Code | Minimum Valley Point Current | Maximum Time At Peak Reflow Temperature (s) | Peak Reflow Temperature (C) | Maximum Peak Point Current |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Texas Instruments |
SINGLE |
NO |
.3 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
35 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
125 Cel |
SILICON |
-65 Cel |
.56 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
BASE2 |
Not Qualified |
.75 |
4.7 kohm |
TO-18 |
4 mA |
NOT SPECIFIED |
NOT SPECIFIED |
5 mA |
||||
|
Nte Electronics |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
55 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
SILICON |
.54 |
12 kohm |
BOTTOM |
O-MBCY-W3 |
Not Qualified |
.67 |
4 kohm |
TO-39 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
25 mA |
||||||
|
|
Nte Electronics |
SINGLE |
NO |
.3 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
35 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
SILICON |
.56 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
BASE2 |
Not Qualified |
.75 |
4.7 kohm |
TO-18 |
4 mA |
NOT SPECIFIED |
NOT SPECIFIED |
5 mA |
|||||
|
|
Nte Electronics |
SINGLE |
NO |
.3 W |
PLASTIC/EPOXY |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
35 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
SILICON |
.7 |
9.1 kohm |
BOTTOM |
O-PBCY-W3 |
Not Qualified |
.85 |
4 kohm |
TO-92 |
4 mA |
NOT SPECIFIED |
NOT SPECIFIED |
5 mA |
||||||
|
Texas Instruments |
SINGLE |
NO |
.36 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
25 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
200 Cel |
SILICON |
-65 Cel |
.55 |
12 kohm |
BOTTOM |
O-MBCY-W3 |
BASE2 |
Not Qualified |
.82 |
4 kohm |
TO-18 |
2 mA |
NOT SPECIFIED |
NOT SPECIFIED |
2 mA |
||||
|
Motorola |
NO |
.36 W |
50 mA |
35 V |
Unijunction Transistors |
125 Cel |
-65 Cel |
Tin/Lead (Sn/Pb) |
.72 |
8.5 kohm |
.8 |
6 kohm |
e0 |
2 mA |
4 mA |
||||||||||||||||||
|
Motorola |
SINGLE |
NO |
METAL |
SWITCHING |
WIRE |
ROUND |
1 |
3 |
CYLINDRICAL |
SILICON |
BOTTOM |
O-MBCY-W3 |
Not Qualified |
TO-206AA |
2 mA |
2 mA |
|||||||||||||||||
|
Texas Instruments |
SINGLE |
NO |
.3 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
35 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
125 Cel |
SILICON |
-65 Cel |
.7 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
BASE2 |
Not Qualified |
.85 |
4.7 kohm |
TO-18 |
4 mA |
NOT SPECIFIED |
NOT SPECIFIED |
2 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.51 |
6.8 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.62 |
4.7 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
12 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.51 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.62 |
6.2 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
12 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.3 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
35 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
200 Cel |
SILICON |
-65 Cel |
.56 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
BASE2 |
Not Qualified |
.75 |
4.7 kohm |
TO-18 |
2 mA |
NOT SPECIFIED |
NOT SPECIFIED |
2 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.56 |
6.8 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.68 |
4.7 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
12 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
35 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.47 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.62 |
4.7 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
6 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.51 |
6.8 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.62 |
4.7 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
12 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.56 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.68 |
6.2 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
12 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.51 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.62 |
6.2 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
6 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.3 W |
PLASTIC/EPOXY |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
25 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
150 Cel |
SILICON |
-55 Cel |
.74 |
12 kohm |
BOTTOM |
O-PBCY-W3 |
Not Qualified |
.86 |
4 kohm |
2 mA |
NOT SPECIFIED |
NOT SPECIFIED |
1 mA |
||||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.62 |
6.8 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.75 |
4.7 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
6 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.3 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
35 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
125 Cel |
SILICON |
-65 Cel |
.7 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
BASE2 |
Not Qualified |
.85 |
4.7 kohm |
TO-18 |
6 mA |
NOT SPECIFIED |
NOT SPECIFIED |
.4 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.62 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
Not Qualified |
.75 |
6.2 kohm |
TO-5 |
12 mA |
NOT SPECIFIED |
NOT SPECIFIED |
2 mA |
||||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.62 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
Not Qualified |
.75 |
6.2 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
15 mA |
||||||
|
Texas Instruments |
SINGLE |
NO |
.3 W |
PLASTIC/EPOXY |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
25 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
150 Cel |
SILICON |
-55 Cel |
.55 |
12 kohm |
BOTTOM |
O-PBCY-W3 |
Not Qualified |
.82 |
4 kohm |
2 mA |
NOT SPECIFIED |
NOT SPECIFIED |
2 mA |
||||||
|
Texas Instruments |
SINGLE |
NO |
.36 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
25 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
200 Cel |
SILICON |
-65 Cel |
.74 |
12 kohm |
BOTTOM |
O-MBCY-W3 |
BASE2 |
Not Qualified |
.86 |
4 kohm |
TO-18 |
2 mA |
NOT SPECIFIED |
NOT SPECIFIED |
1 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
35 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.47 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.62 |
4.7 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
25 mA |
||||
|
Texas Instruments |
NO |
.45 W |
70 mA |
65 V |
Unijunction Transistors |
140 Cel |
-65 Cel |
.62 |
9.1 kohm |
.75 |
6.2 kohm |
8 mA |
6 mA |
||||||||||||||||||||
|
Texas Instruments |
Not Qualified |
||||||||||||||||||||||||||||||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.56 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.68 |
6.2 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
12 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.51 |
6.8 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.62 |
4.7 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
6 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.3 W |
PLASTIC/EPOXY |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
25 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
150 Cel |
SILICON |
-55 Cel |
.51 |
9.1 kohm |
BOTTOM |
O-PBCY-W3 |
Not Qualified |
.69 |
4 kohm |
4 mA |
NOT SPECIFIED |
NOT SPECIFIED |
2 mA |
||||||
|
Texas Instruments |
SINGLE |
NO |
.36 W |
PLASTIC/EPOXY |
SWITCHING |
WIRE |
ROUND |
1 |
3 |
CYLINDRICAL |
Unijunction Transistors |
SILICON |
9.1 kohm |
BOTTOM |
O-PBCY-W3 |
Not Qualified |
.82 |
TO-92 |
2 mA |
NOT SPECIFIED |
NOT SPECIFIED |
5 mA |
|||||||||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
35 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.47 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.62 |
4.7 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
25 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
35 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
150 Cel |
SILICON |
-65 Cel |
.47 |
12 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.8 |
4 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
25 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.56 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.68 |
6.2 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
6 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.56 |
6.8 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.68 |
4.7 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
6 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
METAL |
WIRE |
ROUND |
1 |
3 |
CYLINDRICAL |
SILICON |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
8 mA |
12 mA |
||||||||||||||||||
|
Texas Instruments |
SINGLE |
NO |
.36 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
35 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
200 Cel |
SILICON |
-65 Cel |
.68 |
8 kohm |
BOTTOM |
O-MBCY-W3 |
BASE2 |
Not Qualified |
.82 |
4 kohm |
TO-18 |
1 mA |
NOT SPECIFIED |
NOT SPECIFIED |
2 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.56 |
6.8 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.68 |
4.7 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
12 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.36 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
25 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
200 Cel |
SILICON |
-65 Cel |
.51 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
BASE2 |
Not Qualified |
.69 |
4 kohm |
TO-18 |
4 mA |
NOT SPECIFIED |
NOT SPECIFIED |
2 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.3 W |
PLASTIC/EPOXY |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
25 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
150 Cel |
SILICON |
-55 Cel |
.55 |
9.1 kohm |
BOTTOM |
O-PBCY-W3 |
Not Qualified |
.82 |
4 kohm |
2 mA |
NOT SPECIFIED |
NOT SPECIFIED |
5 mA |
||||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.62 |
6.8 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.75 |
4.7 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
12 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.62 |
6.8 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.75 |
4.7 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
12 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
.51 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
ISOLATED |
Not Qualified |
.62 |
6.2 kohm |
TO-5 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
12 mA |
||||
|
Texas Instruments |
SINGLE |
NO |
.3 W |
METAL |
SWITCHING |
50 mA |
WIRE |
ROUND |
1 |
35 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
125 Cel |
SILICON |
-65 Cel |
.68 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
BASE2 |
Not Qualified |
.82 |
4.7 kohm |
TO-18 |
8 mA |
NOT SPECIFIED |
NOT SPECIFIED |
2 mA |
||||
|
Onsemi |
SINGLE |
NO |
.3 W |
METAL |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
Tin/Lead (Sn/Pb) |
.56 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
.68 |
6.2 kohm |
TO-18 |
e0 |
8 mA |
6 mA |
|||||||
|
Onsemi |
SINGLE |
NO |
.45 W |
METAL |
SWITCHING |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
Tin/Lead (Sn/Pb) |
.56 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
.68 |
6.2 kohm |
TO-5 |
e0 |
8 mA |
2 mA |
||||||
|
Onsemi |
SINGLE |
NO |
.3 W |
METAL |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
TIN LEAD |
.62 |
6.8 kohm |
BOTTOM |
O-MBCY-W3 |
Not Qualified |
.75 |
4.7 kohm |
TO-18 |
e0 |
8 mA |
6 mA |
||||||
|
Onsemi |
SINGLE |
NO |
.3 W |
METAL |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
Tin/Lead (Sn/Pb) |
.62 |
9.1 kohm |
BOTTOM |
O-MBCY-W3 |
.75 |
6.2 kohm |
TO-18 |
e0 |
8 mA |
12 mA |
|||||||
|
Onsemi |
SINGLE |
NO |
.3 W |
METAL |
70 mA |
WIRE |
ROUND |
1 |
65 V |
3 |
CYLINDRICAL |
Unijunction Transistors |
140 Cel |
SILICON |
-65 Cel |
Tin/Lead (Sn/Pb) |
.56 |
6.8 kohm |
BOTTOM |
O-MBCY-W3 |
.68 |
4.7 kohm |
TO-18 |
e0 |
8 mA |
6 mA |
Unijunction Transistors (UJT) are three-terminal semiconductor devices that are used in a variety of applications such as timing, triggering, and oscillation circuits.
A UJT consists of a lightly doped n-type silicon bar with a p-type material implanted in the center, forming two p-n junctions. The two outer ends of the n-type bar are the emitter (E) and collector (C) terminals, while the p-type material in the center is the base (B) terminal. The UJT has a high input impedance and a low output impedance.
When a voltage is applied to the emitter terminal, it causes a small forward bias on the emitter-base junction, which allows a small current to flow into the base region. As the voltage across the UJT increases, the emitter-base junction reaches a point where the current into the base region increases rapidly. This point is known as the "peak-point voltage" or Vp. Once the emitter-base junction is forward biased, the UJT behaves like a negative resistance device, with the current increasing as the voltage decreases.
UJTs are often used in relaxation oscillator circuits and as voltage-controlled switches. In oscillator circuits, the UJT is used to provide a timing signal that can be used to trigger other devices, such as thyristors or triacs. In switching applications, the UJT is used to control the turn-on and turn-off of other devices, such as transistors or SCRs.