3290:, the operating point of the transistor can be made independent of β. In this circuit, the voltage divider holds the base voltage fixed (independent of base current), provided the divider current is large compared to the base current. However, even with a fixed base voltage, collector current varies with temperature (for example) so an emitter resistor is added to stabilize the Q-point, similar to the above circuits with emitter resistor. The voltage divider configuration achieves the correct voltages by the use of resistors in certain patterns. By manipulating the resistors in certain ways you can achieve more stable current levels without having β value affect it too much.
168:
2636:
4337:
4664:
885:
3260:
2627:
application of Miller's
Theorem. This situation is similar to that of an inverting op-amp circuit where the input impedance of the amplifier at the virtual earth is near zero and the overall input impedance is determined by the external series resistor. Due to the gain reduction from feedback, this biasing form is used only when the trade-off for stability is warranted. Adding an emitter resistor to this circuit will increase the input impedance
243:
66:
25:
4432:
476:
4149:
1213:
1463:
2361:
3139:
3904:
3564:
1057:
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D1 and D2 provide a small amount of constant voltage bias for the output pair, just biasing them into the conducting state so that crossover distortion is minimized. That is, the diodes push the output stage into class-AB mode (assuming that the base-emitter drop of the output transistors is reduced
2626:
In this configuration, which is known as "voltage-shunt feedback', the output voltage is sensed and the feedback signal (a current) is applied in shunt (i.e., in parallel with the input). This means that the input impedance "looking into the base" is actually reduced. This can easily be verified by
2618:
stability. However, a T (R-C-R) network can be used to reduce the AC feedback, which however poses a heavier load on the collector than the simple feedback resistor. At higher frequencies a R-L feedback network can be used, however, it will introduce peaking into the frequency response at various
436:
The transistor can be biased so that its collector is normally less than half of the power supply voltage, which implies that collector–emitter power dissipation is at its maximum value. Runaway is then impossible because increasing collector current leads to a decrease in dissipated power; this
4686:
This design automatically stabilizes its operating point, since overall feedback internally operates from DC up through the audio range and beyond. The use of fixed diode bias requires the diodes to be both electrically and thermally matched to the output transistors. If the output transistors
871:
Due to the above inherent drawbacks, fixed bias is rarely used in linear circuits (i.e., those circuits which use the transistor as a current source). Instead, it is often used in circuits where the transistor is used as a switch. However, one application of fixed bias is to achieve crude
1673:
2193:
3876:
1271:
4690:
A common solution to help stabilize the output device operating point is to include some emitter resistors, typically an ohm or so. Calculating the values of the circuit's resistors and capacitors is done based on the components employed and the intended use of the amplifier.
2972:
366:(does not shift to operation in the saturation region or cut-off region) across the input signal's range. Often, the Q-point is established near the center of the active region of a transistor characteristic to allow similar signal swings in positive and negative directions.
277:. The voltage divider configuration achieves the correct voltages by the use of resistors in certain patterns. By selecting the proper resistor values, stable current levels can be achieved that vary only little over temperature and with transistor properties such as
3356:
4144:{\displaystyle I_{\text{c}}=\beta I_{\text{b}}=\beta {\frac {{\frac {V_{\text{cc}}}{1+R_{1}/R_{2}}}-V_{\text{be}}}{(\beta +1)R_{\text{e}}+R_{1}\parallel R_{2}}}\approx {\frac {{\frac {V_{\text{cc}}}{1+R_{1}/R_{2}}}-V_{\text{be}}}{R_{\text{e}}}},}
3247:
The feedback also increases the input impedance of the amplifier when seen from the base, which can be advantageous. Due to the above disadvantages, this type of biasing circuit is used only with careful consideration of the trade-offs involved.
2949:
1805:
1208:{\displaystyle V_{{\text{R}}_{\text{b}}}=V_{\text{cc}}\,-\,{\mathord {\overbrace {(I_{\text{c}}+I_{\text{b}})R_{\text{c}}} ^{{\text{Voltage drop across }}R_{\text{c}}}}}\,-\,{\mathord {\overbrace {V_{\text{be}}} ^{\text{Voltage at base}}}}.}
3727:
4677:
stage that provides amplification of the signal and the DC bias current through D1 and D2 to generate a bias voltage for the output devices. The output pair are arranged in class-AB push–pull, also called a complementary pair. The
2732:
564:
4637:
amplifiers employ 2 active devices to cover the complete 360 deg of input signal flow. Each transistor is therefore biased to perform over approximately 180 deg of the input signal. Class B bias is when the collector current
413:
will also increase. Depending on the bias point, the power dissipated in the transistor may also increase, which will further increase its temperature and exacerbate the problem. This deleterious positive feedback results in
4525:
3732:
1542:
842:
Since the bias is set by the base current, the collector current is directly proportional to β. Therefore, the operating point will vary significantly when transistors are swapped and it is unstable under changes in
764:
2797:
347:
A bias circuit may be composed of only resistors, or may include elements such as temperature-dependent resistors, diodes, or additional voltage sources, depending on the range of operating conditions expected.
1534:
4217:
1458:{\displaystyle V_{{\text{R}}_{\text{b}}}=V_{\text{cc}}-(\overbrace {\beta I_{\text{b}}} ^{I_{\text{c}}}+I_{\text{b}})R_{\text{c}}-V_{\text{be}}=V_{\text{cc}}-I_{\text{b}}(\beta +1)R_{\text{c}}-V_{\text{be}}.}
330:
The gain of a transistor can vary significantly between different batches, which results in widely different operating points for sequential units in serial production or after replacement of a transistor.
3632:
2356:{\displaystyle I_{\text{c}}=\beta I_{\text{b}}={\frac {\beta (V_{\text{cc}}-V_{\text{be}})}{R_{\text{b}}+R_{\text{c}}+\beta R_{\text{c}}}}\approx {\frac {(V_{\text{cc}}-V_{\text{be}})}{R_{\text{c}}}}}
3197:
2407:
691:
4599:
3134:{\displaystyle I_{\text{c}}=\beta I_{\text{b}}={\frac {\beta (V_{\text{cc}}-V_{\text{be}})}{R_{\text{b}}+(\beta +1)R_{\text{e}}}}\approx {\frac {(V_{\text{cc}}-V_{\text{be}})}{R_{\text{e}}}}}
1263:
2855:
4439:
When a split supply (dual power supply) is available, this biasing circuit is the most effective. It provides zero bias voltage at the emitter or collector for load. The negative supply V
813:
4410:
4310:, reducing the allowed collector current. Lowering both resistor values draws more current from the power supply and lowers the input resistance of the amplifier as seen from the base.
1952:
1022:
3640:
1711:
2542:
2099:
2072:
1835:
952:
3559:{\displaystyle V_{\text{b}}=V_{\text{cc}}{\frac {R_{2}}{(R_{1}+R_{2})}}-I_{\text{b}}{\frac {R_{1}R_{2}}{(R_{1}+R_{2})}}\approx V_{\text{cc}}{\frac {R_{2}}{(R_{1}+R_{2})}}}
2654:
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2033:
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1979:
1916:
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1703:
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979:
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326:
A bias network is selected to stabilize the operating point of the transistor, by reducing the following effects of device variability, temperature, and voltage changes:
496:
3321:
644:
427:
can be built into the biasing circuit so that increased collector current leads to decreased base current. Hence, the increasing collector current throttles its source.
4461:
3351:
2429:
2188:
4551:
2574:
is low, the reverse bias of the collector–base region is small, which limits the range of collector voltage swing that leaves the transistor in active mode.
700:
846:
For small-signal transistors (e.g., not power transistors) with relatively high values of β (i.e., between 100 and 200), this configuration will be prone to
2741:
4154:
2138:
must be chosen once β is known fairly accurately (perhaps within ~ 25%), yet the variability of β between "identical" parts is often larger than this.
1668:{\displaystyle \overbrace {I_{\text{b}}R_{\text{b}}} ^{V_{{\text{R}}_{\text{b}}}}=V_{\text{cc}}-I_{\text{b}}(\beta +1)R_{\text{c}}-V_{\text{be}}.}
4606:
Only two resistors are necessary for the common collector configuration. (And four resistors for a common emitter or common base configuration.)
3144:
4687:
conduct too much, they can easily overheat and destroy themselves, as the full current from the power supply is not limited at this stage.
2366:
1475:
130:
83:
38:
3871:{\displaystyle I_{\text{b}}={\frac {{\frac {V_{\text{cc}}}{1+R_{1}/R_{2}}}-V_{\text{be}}}{(\beta +1)R_{\text{e}}+R_{1}\parallel R_{2}}}}
2823:
across the base resistor. A lower base-resistor voltage drop reduces the base current, which results in less collector current because I
649:
369:
For digital operation, the Q-point is instead chosen so the transistor switches from the "on" (saturation) to the "off" (cutoff) state.
2846:(corresponding to change in β-value, for example). By similar process as above, the change is negated and operating point kept stable.
102:
601:
4319:, which reduces the AC voltage gain of the amplifier. A method to avoid AC feedback while retaining DC feedback is discussed below.
3569:
3229:
is low, a separate low voltage supply should be used in the base circuit. Using two supplies of different voltages is impractical.
109:
862:
of the amplifier, a stability factor of less than 25 is preferred, and so small-signal transistors have large stability factors.
388:
by 2 mV (silicon) and 1.8 mV (germanium) for each 1 °C rise in temperature (reference being 25 °C). By the
362:
116:
98:
4814:
4772:
4742:
4642:
with no signal is just conducting (about 1% of maximum possible value). Class-AB bias is when the collector current I
4556:
1225:
229:
211:
189:
149:
52:
4808:
2839:
with α ≈ 1, so the increase in emitter current with temperature is opposed, and the operating point is kept stable.
182:
261:
to operate correctly. In circuits made with individual devices (discrete circuits), biasing networks consisting of
567:
4829:
2431:-value is fixed (and generally unknown) for a given transistor, this relation can be satisfied either by keeping
44:
2044:
Circuit stabilizes the operating point against variations in temperature and β (i.e. replacement of transistor).
769:
4373:
1921:
991:
87:
2643:
The fixed bias circuit is modified by attaching an external resistor to the emitter. This resistor introduces
450:
The following discussion treats five common biasing circuits used with class-A bipolar transistor amplifiers:
278:
876:
in the transistor by feeding the base resistor from a DC signal derived from the AC output of a later stage.
2035:. Because an increase in collector current with temperature is opposed, the operating point is kept stable.
4228:
4634:
4710:
4630:
4344:
The standard voltage divider circuit discussed above faces a drawback – AC feedback caused by resistor R
123:
2944:{\displaystyle I_{\text{b}}={\frac {V_{\text{cc}}-V_{\text{be}}}{R_{\text{b}}+(\beta +1)R_{\text{e}}}}}
2648:
1800:{\displaystyle I_{\text{b}}={\frac {V_{\text{cc}}-V_{\text{be}}}{R_{\text{b}}+(\beta +1)R_{\text{c}}}}}
985:
2956:
The circuit has the tendency to stabilize operating point against changes in temperature and β-value.
270:
4764:
2520:
2077:
2050:
1813:
930:
176:
4370:
The AC-gain is much higher (approaching β), rather than the much lower (but predictable) value of
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2146:
2114:
2011:
1984:
1957:
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1840:
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957:
903:
441:
The circuits below primarily demonstrate the use of negative feedback to prevent thermal runaway.
247:
76:
2111:
Although small changes in β are OK, large changes in β will greatly change the operating point.
3722:{\displaystyle V_{\text{b}}=V_{\text{be}}+V_{\text{e}}=V_{\text{be}}+I_{\text{e}}R_{\text{e}}.}
873:
193:
4244:
As β-value is fixed for a given transistor, this relation can be satisfied either by keeping R
3299:
3203:
As β-value is fixed for a given transistor, this relation can be satisfied either by keeping R
622:
4700:
3326:
258:
4756:
2414:
2173:
433:
can be used that carry away extra heat and prevent the base–emitter temperature from rising.
420:. There are several approaches to mitigate bipolar transistor thermal runaway. For example,
4657:
2803:
is held constant and temperature increases, emitter current increases. However, a larger I
1219:
389:
399:
is held constant and the temperature rises, the current through the base–emitter junction
8:
4757:
2607:
266:
4536:
4458:
is small enough, base voltage will be approximately zero. Therefore, emitter current is,
4705:
855:
254:
859:
851:
4768:
4738:
4328:
The circuit's stability and merits as above make it widely used for linear circuits.
2727:{\displaystyle V_{R_{\text{b}}}=V_{\text{cc}}-I_{\text{e}}R_{\text{e}}-V_{\text{be}}}
2644:
893:
424:
357:
2635:
2544:
is necessary, which increases cost as well as precautions necessary while handling.
559:{\displaystyle I_{\text{b}}={\frac {V_{\text{cc}}-V_{\text{be}}}{R_{\text{b}}}}\,.}
4660:
amplifier circuit below could be the basis for a moderate-power audio amplifier.
4267:
is necessary. This increases cost as well as precautions necessary while handling.
3222:
is necessary. This increases cost as well as precautions necessary while handling.
897:
847:
416:
285:
4520:{\displaystyle I_{\text{e}}={\frac {V_{\text{ee}}-V_{\text{be}}}{R_{\text{e}}}}}
854:, which is a measure of the change in collector current with changes in reverse
4674:
2842:
Similarly, if the transistor is replaced by another, there may be a change in I
832:
The operating point is set by two resistors and the calculation is very simple.
582:
579:
301:
274:
3254:
900:
and stabilize the operating point. In this form of biasing, the base resistor
4823:
4298:, reducing the available swing in collector voltage, and limiting how large R
265:
are commonly employed. Much more elaborate biasing arrangements are used in
4336:
2735:
2611:
1469:
334:
4663:
250:
diagram, illustrating an operating point in the transistor's active region
4616:
This type can only be used when a split (dual) power supply is available.
884:
759:{\displaystyle V_{\text{ce}}=V_{\text{cc}}-{I_{\text{c}}R_{\text{c}}}\,.}
3282:
forward biases the emitter junction. By proper selection of resistors R
3259:
1837:
is held constant and temperature increases, then the collector current
4302:
can be made without driving the transistor out of active mode. A low R
2792:{\displaystyle I_{\text{b}}={\frac {V_{R_{\text{b}}}}{R_{\text{b}}}}}
2614:
of the amplifier. This undesirable effect is a trade-off for greater
593:
also doesn't vary significantly. Thus this type of biasing is called
430:
65:
3238:
causes AC feedback which reduces the voltage gain of the amplifier.
1529:{\displaystyle I_{\text{b}}=V_{{\text{R}}_{\text{b}}}/R_{\text{b}}}
262:
242:
4212:{\displaystyle (\beta +1)R_{\text{e}}>>R_{1}\parallel R_{2}}
377:
At constant current, the voltage across the emitter–base junction
2615:
337:, the current gain is affected by the collector–emitter voltage.
4715:
4431:
4348:
reduces the gain. This can be avoided by placing a capacitor (C
954:. So any thermal runaway will induce a voltage drop across the
445:
1981:. A lower base-resistor voltage drop reduces the base current
4679:
4365:
The result is that the DC operating point is well controlled.
475:
340:
Both gain and base–emitter voltage depend on the temperature.
3627:{\displaystyle I_{\text{b}}<<I_{1}=V_{\text{b}}/R_{1}}
2799:
The way feedback controls the bias point is as follows. If V
300:, is the point on the output characteristics that shows the
4331:
3255:
Voltage divider biasing or emitter
Resistor Stabilizer bias
981:
resistor that will throttle the transistor's base current.
604:
of a transistor (specified as a range on its data sheet as
927:
is connected to the collector instead of connecting it to
2047:
Circuit stabilizes the operating point (as a fraction of
3887:
Operating point stabilized against shift in temperature.
2831:. Collector current and emitter current are related by I
3192:{\displaystyle (\beta +1)R_{\text{e}}\gg R_{\text{b}}.}
4559:
4539:
4443:
is used to forward-bias the emitter junction through R
3302:
3268:
The voltage divider is formed using external resistors
772:
625:
16:
Process necessary for BJT amplifiers to work correctly
4815:
4464:
4376:
4157:
3907:
3901:
independent of β the following condition must be met:
3884:
Operating point is almost independent of β variation.
3735:
3643:
3572:
3359:
3329:
3147:
2975:
2969:
independent of β the following condition must be met:
2858:
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2657:
2585:
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2523:
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2464:
2437:
2417:
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2196:
2176:
2149:
2117:
2080:
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2014:
1987:
1960:
1924:
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1870:
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1816:
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1274:
1228:
1060:
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994:
960:
933:
906:
703:
652:
499:
4754:
343:
The leakage current also increases with temperature.
4763:(5th ed.). New York: Oxford University Press.
2630:
2402:{\displaystyle \beta R_{\text{c}}\gg R_{\text{b}}.}
360:, the Q-point is placed so the transistor stays in
90:. Unsourced material may be challenged and removed.
4593:
4545:
4519:
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4143:
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1016:
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807:
758:
686:{\displaystyle I_{\text{c}}=\beta I_{\text{b}}\,.}
685:
638:
574:doesn't vary significantly during use. And since R
558:
4451:is used to reverse-bias the collector junction.
4821:
4594:{\textstyle R_{\text{e}}\gg R_{\text{b}}/\beta }
1918:to increase, which in turn reduces the voltage
1258:{\displaystyle I_{\text{c}}=\beta I_{\text{b}}}
406:will increase, and thus the collector current
4791:
4620:
446:Types of bias circuit for class-A amplifiers
321:
4794:Basic Electricity and Semiconductor Devices
808:{\textstyle (V_{\text{ce}},\ I_{\text{c}})}
53:Learn how and when to remove these messages
2008:, which results in less collector current
879:
4405:{\displaystyle R_{\text{c}}/R_{\text{e}}}
2651:, the voltage across the base resistor is
1947:{\displaystyle V_{{\text{R}}_{\text{b}}}}
1173:
1169:
1097:
1093:
1017:{\displaystyle V_{{\text{R}}_{\text{b}}}}
752:
679:
552:
470:
463:Voltage divider bias or potential divider
372:
230:Learn how and when to remove this message
212:Learn how and when to remove this message
150:Learn how and when to remove this message
4662:
4656:of maximum possible value. The class-AB
4625:
4430:
4335:
4332:Voltage divider with AC bypass capacitor
4315:AC as well as DC feedback is caused by R
3258:
2634:
1891:causes the voltage drop across resistor
883:
474:
241:
175:This article includes a list of general
4822:
4533:The operating point is independent of
2190:, the following condition must be met:
351:
4735:The Art of Electronics Second Edition
2819:, which in turn reduces the voltage V
485:base bias or fixed resistance biasing
4755:A.S. Sedra & K.C. Smith (2004).
4748:
4737:, Cambridge University Press, 1989,
483:This form of biasing is also called
392:, if the base–emitter voltage
161:
88:adding citations to reliable sources
59:
18:
4792:Patil, P.K.; Chitnis, M.M. (2005).
815:for a transistor can be set using R
13:
4811:– from Sci-Tech Encyclopedia
4784:
4151:which is approximately the case if
3296:In this circuit the base voltage,
3141:which is approximately the case if
2647:that stabilizes the Q-point. From
858:, is approximately β+1. To ensure
181:it lacks sufficient corresponding
14:
4841:
4802:
34:This article has multiple issues.
4286:is low, or both are low. A low R
2639:Fixed bias with emitter resistor
2631:Fixed bias with emitter resistor
589:are constant, the base current I
493:In the given fixed bias circuit,
460:Fixed bias with emitter resistor
318:) with no input signal applied.
166:
64:
23:
4426:
4356:, as shown in circuit diagram.
2807:increases the emitter voltage V
75:needs additional citations for
42:or discuss these issues on the
4733:Paul Horowitz, Winfield Hill,
4727:
4340:Voltage divider with capacitor
4170:
4158:
4017:
4005:
3826:
3814:
3550:
3524:
3492:
3466:
3422:
3396:
3251:Collector-Stabilized Biasing.
3160:
3148:
3115:
3089:
3067:
3055:
3037:
3011:
2925:
2913:
2337:
2311:
2258:
2232:
1781:
1769:
1636:
1624:
1426:
1414:
1362:
1310:
1130:
1104:
802:
773:
479:Fixed bias circuit (Base bias)
1:
4721:
4668:A practical amplifier circuit
2537:{\displaystyle V_{\text{cc}}}
2094:{\displaystyle V_{\text{cc}}}
2067:{\displaystyle V_{\text{cc}}}
1864:increases. However, a larger
1830:{\displaystyle V_{\text{be}}}
947:{\displaystyle V_{\text{cc}}}
311:) and the collector current (
4767:, Figure 5.17, and p. 1245.
2599:{\displaystyle R_{\text{b}}}
2567:{\displaystyle R_{\text{b}}}
2510:{\displaystyle R_{\text{c}}}
2478:{\displaystyle R_{\text{b}}}
2451:{\displaystyle R_{\text{c}}}
2163:{\displaystyle I_{\text{c}}}
2131:{\displaystyle R_{\text{b}}}
2028:{\displaystyle I_{\text{c}}}
2001:{\displaystyle I_{\text{b}}}
1974:{\displaystyle R_{\text{b}}}
1911:{\displaystyle R_{\text{c}}}
1884:{\displaystyle I_{\text{c}}}
1857:{\displaystyle I_{\text{c}}}
1698:{\displaystyle I_{\text{b}}}
1044:{\displaystyle R_{\text{b}}}
974:{\displaystyle R_{\text{c}}}
920:{\displaystyle R_{\text{b}}}
99:"Bipolar transistor biasing"
7:
4711:Bipolar junction transistor
4694:
3234:In addition to the above, R
892:This configuration employs
602:common-emitter current gain
304:collector–emitter voltage (
288:of a device, also known as
10:
4846:
3897:In this circuit, to keep I
2965:In this circuit, to keep I
356:For analog operation of a
271:bandgap voltage references
4621:Class-B and AB amplifiers
4263:is of large value, high V
4248:fairly large, or making R
3316:{\textstyle V_{\text{b}}}
3218:is of large value, high V
2143:In this circuit, to keep
1954:across the base resistor
1152:Voltage drop across
1024:across the base resistor
639:{\textstyle I_{\text{c}}}
384:of a bipolar transistor
322:Bias circuit requirements
4759:Microelectronic Circuits
4422:Adds an extra component.
2074:) against variations in
1678:Hence, the base current
766:Thus an operating point
4447:. The positive supply V
3346:{\displaystyle R_{2}\ }
3207:very large, or making R
2649:Kirchhoff's voltage law
2610:feedback, reducing the
2458:fairly large or making
986:Kirchhoff's voltage law
880:Collector feedback bias
619:), allows us to obtain
439:half-voltage principle.
437:notion is known as the
196:more precise citations.
4830:Electronic engineering
4683:by heat dissipation).
4670:
4595:
4547:
4521:
4436:
4412:without the capacitor.
4406:
4341:
4239:connected in parallel.
4213:
4145:
3872:
3729:For the given circuit,
3723:
3628:
3560:
3347:
3317:
3278:. The voltage across R
3264:
3193:
3135:
2945:
2852:For the given circuit,
2793:
2728:
2640:
2600:
2568:
2538:
2511:
2479:
2452:
2425:
2424:{\displaystyle \beta }
2403:
2363:which is the case when
2357:
2184:
2183:{\displaystyle \beta }
2164:
2132:
2095:
2068:
2029:
2002:
1975:
1948:
1912:
1885:
1858:
1831:
1801:
1699:
1669:
1530:
1459:
1259:
1220:Ebers–Moll model
1209:
1045:
1018:
975:
948:
921:
889:
888:Collector-to-base bias
874:automatic gain control
809:
760:
687:
640:
560:
480:
471:Fixed bias (base bias)
457:Collector-to-base bias
390:Ebers–Moll model
373:Thermal considerations
251:
4701:Biasing (electronics)
4666:
4596:
4548:
4522:
4434:
4407:
4339:
4229:equivalent resistance
4214:
4146:
3873:
3724:
3637:It is also known that
3629:
3561:
3348:
3318:
3262:
3194:
3136:
2946:
2794:
2738:, the base current is
2729:
2638:
2601:
2569:
2539:
2512:
2480:
2453:
2426:
2404:
2358:
2185:
2165:
2133:
2096:
2069:
2030:
2003:
1976:
1949:
1913:
1886:
1859:
1832:
1802:
1700:
1670:
1531:
1460:
1260:
1210:
1046:
1019:
976:
949:
922:
887:
850:. In particular, the
810:
761:
688:
641:
561:
478:
245:
4557:
4537:
4462:
4374:
4352:) in parallel with R
4155:
3905:
3733:
3641:
3570:
3357:
3327:
3300:
3263:Voltage divider bias
3145:
2973:
2856:
2742:
2655:
2583:
2551:
2521:
2494:
2462:
2435:
2415:
2367:
2194:
2174:
2147:
2115:
2078:
2051:
2012:
1985:
1958:
1922:
1895:
1868:
1841:
1814:
1712:
1682:
1543:
1476:
1272:
1226:
1058:
1028:
992:
958:
931:
904:
770:
701:
650:
623:
497:
84:improve this article
4796:. Phadke Prakashan.
4626:Signal requirements
4546:{\textstyle \beta }
1472:, the base current
352:Signal requirements
267:integrated circuits
255:Bipolar transistors
4706:Small signal model
4671:
4591:
4543:
4517:
4437:
4402:
4342:
4209:
4141:
3868:
3719:
3624:
3556:
3343:
3313:
3265:
3189:
3131:
2941:
2789:
2724:
2641:
2596:
2564:
2534:
2507:
2475:
2448:
2421:
2399:
2353:
2180:
2160:
2128:
2091:
2064:
2025:
1998:
1971:
1944:
1908:
1881:
1854:
1827:
1797:
1695:
1665:
1526:
1455:
1255:
1205:
1041:
1014:
971:
944:
917:
890:
860:absolute stability
856:saturation current
805:
756:
697:can be determined:
683:
636:
568:a given transistor
556:
481:
252:
4580:
4567:
4515:
4512:
4501:
4488:
4472:
4399:
4384:
4180:
4136:
4133:
4122:
4110:
4074:
4057:
4027:
4000:
3988:
3952:
3931:
3915:
3866:
3836:
3809:
3797:
3761:
3743:
3713:
3703:
3690:
3677:
3664:
3651:
3606:
3580:
3554:
3508:
3496:
3438:
3426:
3380:
3367:
3342:
3310:
3183:
3170:
3129:
3126:
3112:
3099:
3081:
3077:
3049:
3034:
3021:
2999:
2983:
2939:
2935:
2907:
2895:
2882:
2866:
2787:
2784:
2772:
2752:
2721:
2708:
2698:
2685:
2670:
2645:negative feedback
2593:
2561:
2531:
2517:is large, a high
2504:
2472:
2445:
2393:
2380:
2351:
2348:
2334:
2321:
2303:
2299:
2283:
2270:
2255:
2242:
2220:
2204:
2157:
2125:
2088:
2061:
2022:
1995:
1968:
1939:
1934:
1905:
1878:
1851:
1824:
1795:
1791:
1763:
1751:
1738:
1722:
1692:
1659:
1646:
1621:
1608:
1597:
1591:
1586:
1574:
1567:
1557:
1523:
1506:
1501:
1486:
1449:
1436:
1411:
1398:
1385:
1372:
1359:
1348:
1344:
1334:
1327:
1304:
1289:
1284:
1252:
1236:
1199:
1197:
1192:
1186:
1166:
1162:
1153:
1147:
1140:
1127:
1114:
1090:
1075:
1070:
1038:
1009:
1004:
968:
941:
914:
894:negative feedback
799:
791:
783:
748:
738:
724:
711:
676:
660:
633:
550:
547:
536:
523:
507:
425:Negative feedback
358:class-A amplifier
257:must be properly
240:
239:
232:
222:
221:
214:
160:
159:
152:
134:
57:
4837:
4797:
4779:
4778:
4762:
4752:
4746:
4731:
4658:push–pull output
4655:
4654:
4650:
4600:
4598:
4597:
4592:
4587:
4582:
4581:
4578:
4569:
4568:
4565:
4552:
4550:
4549:
4544:
4526:
4524:
4523:
4518:
4516:
4514:
4513:
4510:
4504:
4503:
4502:
4499:
4490:
4489:
4486:
4479:
4474:
4473:
4470:
4411:
4409:
4408:
4403:
4401:
4400:
4397:
4391:
4386:
4385:
4382:
4278:is low, either R
4218:
4216:
4215:
4210:
4208:
4207:
4195:
4194:
4182:
4181:
4178:
4150:
4148:
4147:
4142:
4137:
4135:
4134:
4131:
4125:
4124:
4123:
4120:
4111:
4109:
4108:
4107:
4098:
4093:
4092:
4076:
4075:
4072:
4066:
4063:
4058:
4056:
4055:
4054:
4042:
4041:
4029:
4028:
4025:
4003:
4002:
4001:
3998:
3989:
3987:
3986:
3985:
3976:
3971:
3970:
3954:
3953:
3950:
3944:
3941:
3933:
3932:
3929:
3917:
3916:
3913:
3877:
3875:
3874:
3869:
3867:
3865:
3864:
3863:
3851:
3850:
3838:
3837:
3834:
3812:
3811:
3810:
3807:
3798:
3796:
3795:
3794:
3785:
3780:
3779:
3763:
3762:
3759:
3753:
3750:
3745:
3744:
3741:
3728:
3726:
3725:
3720:
3715:
3714:
3711:
3705:
3704:
3701:
3692:
3691:
3688:
3679:
3678:
3675:
3666:
3665:
3662:
3653:
3652:
3649:
3633:
3631:
3630:
3625:
3623:
3622:
3613:
3608:
3607:
3604:
3595:
3594:
3582:
3581:
3578:
3565:
3563:
3562:
3557:
3555:
3553:
3549:
3548:
3536:
3535:
3522:
3521:
3512:
3510:
3509:
3506:
3497:
3495:
3491:
3490:
3478:
3477:
3464:
3463:
3462:
3453:
3452:
3442:
3440:
3439:
3436:
3427:
3425:
3421:
3420:
3408:
3407:
3394:
3393:
3384:
3382:
3381:
3378:
3369:
3368:
3365:
3352:
3350:
3349:
3344:
3340:
3339:
3338:
3322:
3320:
3319:
3314:
3312:
3311:
3308:
3198:
3196:
3195:
3190:
3185:
3184:
3181:
3172:
3171:
3168:
3140:
3138:
3137:
3132:
3130:
3128:
3127:
3124:
3118:
3114:
3113:
3110:
3101:
3100:
3097:
3087:
3082:
3080:
3079:
3078:
3075:
3051:
3050:
3047:
3040:
3036:
3035:
3032:
3023:
3022:
3019:
3006:
3001:
3000:
2997:
2985:
2984:
2981:
2950:
2948:
2947:
2942:
2940:
2938:
2937:
2936:
2933:
2909:
2908:
2905:
2898:
2897:
2896:
2893:
2884:
2883:
2880:
2873:
2868:
2867:
2864:
2798:
2796:
2795:
2790:
2788:
2786:
2785:
2782:
2776:
2775:
2774:
2773:
2770:
2759:
2754:
2753:
2750:
2733:
2731:
2730:
2725:
2723:
2722:
2719:
2710:
2709:
2706:
2700:
2699:
2696:
2687:
2686:
2683:
2674:
2673:
2672:
2671:
2668:
2605:
2603:
2602:
2597:
2595:
2594:
2591:
2573:
2571:
2570:
2565:
2563:
2562:
2559:
2543:
2541:
2540:
2535:
2533:
2532:
2529:
2516:
2514:
2513:
2508:
2506:
2505:
2502:
2484:
2482:
2481:
2476:
2474:
2473:
2470:
2457:
2455:
2454:
2449:
2447:
2446:
2443:
2430:
2428:
2427:
2422:
2408:
2406:
2405:
2400:
2395:
2394:
2391:
2382:
2381:
2378:
2362:
2360:
2359:
2354:
2352:
2350:
2349:
2346:
2340:
2336:
2335:
2332:
2323:
2322:
2319:
2309:
2304:
2302:
2301:
2300:
2297:
2285:
2284:
2281:
2272:
2271:
2268:
2261:
2257:
2256:
2253:
2244:
2243:
2240:
2227:
2222:
2221:
2218:
2206:
2205:
2202:
2189:
2187:
2186:
2181:
2169:
2167:
2166:
2161:
2159:
2158:
2155:
2137:
2135:
2134:
2129:
2127:
2126:
2123:
2100:
2098:
2097:
2092:
2090:
2089:
2086:
2073:
2071:
2070:
2065:
2063:
2062:
2059:
2034:
2032:
2031:
2026:
2024:
2023:
2020:
2007:
2005:
2004:
1999:
1997:
1996:
1993:
1980:
1978:
1977:
1972:
1970:
1969:
1966:
1953:
1951:
1950:
1945:
1943:
1942:
1941:
1940:
1937:
1935:
1932:
1917:
1915:
1914:
1909:
1907:
1906:
1903:
1890:
1888:
1887:
1882:
1880:
1879:
1876:
1863:
1861:
1860:
1855:
1853:
1852:
1849:
1836:
1834:
1833:
1828:
1826:
1825:
1822:
1806:
1804:
1803:
1798:
1796:
1794:
1793:
1792:
1789:
1765:
1764:
1761:
1754:
1753:
1752:
1749:
1740:
1739:
1736:
1729:
1724:
1723:
1720:
1704:
1702:
1701:
1696:
1694:
1693:
1690:
1674:
1672:
1671:
1666:
1661:
1660:
1657:
1648:
1647:
1644:
1623:
1622:
1619:
1610:
1609:
1606:
1596:
1595:
1594:
1593:
1592:
1589:
1587:
1584:
1575:
1570:
1569:
1568:
1565:
1559:
1558:
1555:
1548:
1546:
1535:
1533:
1532:
1527:
1525:
1524:
1521:
1515:
1510:
1509:
1508:
1507:
1504:
1502:
1499:
1488:
1487:
1484:
1464:
1462:
1461:
1456:
1451:
1450:
1447:
1438:
1437:
1434:
1413:
1412:
1409:
1400:
1399:
1396:
1387:
1386:
1383:
1374:
1373:
1370:
1361:
1360:
1357:
1347:
1346:
1345:
1342:
1335:
1330:
1329:
1328:
1325:
1315:
1313:
1306:
1305:
1302:
1293:
1292:
1291:
1290:
1287:
1285:
1282:
1264:
1262:
1261:
1256:
1254:
1253:
1250:
1238:
1237:
1234:
1214:
1212:
1211:
1206:
1201:
1200:
1198:
1195:
1193:
1188:
1187:
1184:
1178:
1176:
1168:
1167:
1165:
1164:
1163:
1160:
1154:
1151:
1148:
1143:
1142:
1141:
1138:
1129:
1128:
1125:
1116:
1115:
1112:
1102:
1100:
1092:
1091:
1088:
1079:
1078:
1077:
1076:
1073:
1071:
1068:
1050:
1048:
1047:
1042:
1040:
1039:
1036:
1023:
1021:
1020:
1015:
1013:
1012:
1011:
1010:
1007:
1005:
1002:
980:
978:
977:
972:
970:
969:
966:
953:
951:
950:
945:
943:
942:
939:
926:
924:
923:
918:
916:
915:
912:
852:stability factor
814:
812:
811:
806:
801:
800:
797:
789:
785:
784:
781:
765:
763:
762:
757:
751:
750:
749:
746:
740:
739:
736:
726:
725:
722:
713:
712:
709:
692:
690:
689:
684:
678:
677:
674:
662:
661:
658:
645:
643:
642:
637:
635:
634:
631:
617:
608:
565:
563:
562:
557:
551:
549:
548:
545:
539:
538:
537:
534:
525:
524:
521:
514:
509:
508:
505:
235:
228:
217:
210:
206:
203:
197:
192:this article by
183:inline citations
170:
169:
162:
155:
148:
144:
141:
135:
133:
92:
68:
60:
49:
27:
26:
19:
4845:
4844:
4840:
4839:
4838:
4836:
4835:
4834:
4820:
4819:
4805:
4800:
4787:
4785:Further reading
4782:
4775:
4753:
4749:
4732:
4728:
4724:
4697:
4669:
4652:
4648:
4647:
4645:
4641:
4628:
4623:
4583:
4577:
4573:
4564:
4560:
4558:
4555:
4554:
4538:
4535:
4534:
4509:
4505:
4498:
4494:
4485:
4481:
4480:
4478:
4469:
4465:
4463:
4460:
4459:
4457:
4450:
4446:
4442:
4429:
4396:
4392:
4387:
4381:
4377:
4375:
4372:
4371:
4355:
4351:
4347:
4334:
4318:
4309:
4305:
4301:
4297:
4293:
4289:
4285:
4281:
4277:
4273:
4266:
4262:
4255:
4251:
4247:
4238:
4234:
4226:
4222:
4203:
4199:
4190:
4186:
4177:
4173:
4156:
4153:
4152:
4130:
4126:
4119:
4115:
4103:
4099:
4094:
4088:
4084:
4077:
4071:
4067:
4065:
4064:
4062:
4050:
4046:
4037:
4033:
4024:
4020:
4004:
3997:
3993:
3981:
3977:
3972:
3966:
3962:
3955:
3949:
3945:
3943:
3942:
3940:
3928:
3924:
3912:
3908:
3906:
3903:
3902:
3900:
3859:
3855:
3846:
3842:
3833:
3829:
3813:
3806:
3802:
3790:
3786:
3781:
3775:
3771:
3764:
3758:
3754:
3752:
3751:
3749:
3740:
3736:
3734:
3731:
3730:
3710:
3706:
3700:
3696:
3687:
3683:
3674:
3670:
3661:
3657:
3648:
3644:
3642:
3639:
3638:
3618:
3614:
3609:
3603:
3599:
3590:
3586:
3577:
3573:
3571:
3568:
3567:
3544:
3540:
3531:
3527:
3523:
3517:
3513:
3511:
3505:
3501:
3486:
3482:
3473:
3469:
3465:
3458:
3454:
3448:
3444:
3443:
3441:
3435:
3431:
3416:
3412:
3403:
3399:
3395:
3389:
3385:
3383:
3377:
3373:
3364:
3360:
3358:
3355:
3354:
3334:
3330:
3328:
3325:
3324:
3307:
3303:
3301:
3298:
3297:
3293:
3289:
3285:
3281:
3277:
3273:
3257:
3237:
3228:
3221:
3217:
3210:
3206:
3180:
3176:
3167:
3163:
3146:
3143:
3142:
3123:
3119:
3109:
3105:
3096:
3092:
3088:
3086:
3074:
3070:
3046:
3042:
3041:
3031:
3027:
3018:
3014:
3007:
3005:
2996:
2992:
2980:
2976:
2974:
2971:
2970:
2968:
2932:
2928:
2904:
2900:
2899:
2892:
2888:
2879:
2875:
2874:
2872:
2863:
2859:
2857:
2854:
2853:
2849:
2845:
2838:
2834:
2830:
2826:
2822:
2818:
2814:
2810:
2806:
2802:
2781:
2777:
2769:
2765:
2764:
2760:
2758:
2749:
2745:
2743:
2740:
2739:
2718:
2714:
2705:
2701:
2695:
2691:
2682:
2678:
2667:
2663:
2662:
2658:
2656:
2653:
2652:
2633:
2590:
2586:
2584:
2581:
2580:
2558:
2554:
2552:
2549:
2548:
2528:
2524:
2522:
2519:
2518:
2501:
2497:
2495:
2492:
2491:
2469:
2465:
2463:
2460:
2459:
2442:
2438:
2436:
2433:
2432:
2416:
2413:
2412:
2390:
2386:
2377:
2373:
2368:
2365:
2364:
2345:
2341:
2331:
2327:
2318:
2314:
2310:
2308:
2296:
2292:
2280:
2276:
2267:
2263:
2262:
2252:
2248:
2239:
2235:
2228:
2226:
2217:
2213:
2201:
2197:
2195:
2192:
2191:
2175:
2172:
2171:
2170:independent of
2154:
2150:
2148:
2145:
2144:
2122:
2118:
2116:
2113:
2112:
2085:
2081:
2079:
2076:
2075:
2058:
2054:
2052:
2049:
2048:
2019:
2015:
2013:
2010:
2009:
1992:
1988:
1986:
1983:
1982:
1965:
1961:
1959:
1956:
1955:
1936:
1931:
1930:
1929:
1925:
1923:
1920:
1919:
1902:
1898:
1896:
1893:
1892:
1875:
1871:
1869:
1866:
1865:
1848:
1844:
1842:
1839:
1838:
1821:
1817:
1815:
1812:
1811:
1788:
1784:
1760:
1756:
1755:
1748:
1744:
1735:
1731:
1730:
1728:
1719:
1715:
1713:
1710:
1709:
1689:
1685:
1683:
1680:
1679:
1656:
1652:
1643:
1639:
1618:
1614:
1605:
1601:
1588:
1583:
1582:
1581:
1577:
1576:
1564:
1560:
1554:
1550:
1549:
1547:
1544:
1541:
1540:
1520:
1516:
1511:
1503:
1498:
1497:
1496:
1492:
1483:
1479:
1477:
1474:
1473:
1446:
1442:
1433:
1429:
1408:
1404:
1395:
1391:
1382:
1378:
1369:
1365:
1356:
1352:
1341:
1337:
1336:
1324:
1320:
1316:
1314:
1301:
1297:
1286:
1281:
1280:
1279:
1275:
1273:
1270:
1269:
1249:
1245:
1233:
1229:
1227:
1224:
1223:
1196:Voltage at base
1194:
1183:
1179:
1177:
1175:
1174:
1159:
1155:
1150:
1149:
1137:
1133:
1124:
1120:
1111:
1107:
1103:
1101:
1099:
1098:
1087:
1083:
1072:
1067:
1066:
1065:
1061:
1059:
1056:
1055:
1035:
1031:
1029:
1026:
1025:
1006:
1001:
1000:
999:
995:
993:
990:
989:
965:
961:
959:
956:
955:
938:
934:
932:
929:
928:
911:
907:
905:
902:
901:
898:thermal runaway
882:
848:thermal runaway
822:
818:
796:
792:
780:
776:
771:
768:
767:
745:
741:
735:
731:
730:
721:
717:
708:
704:
702:
699:
698:
696:
673:
669:
657:
653:
651:
648:
647:
630:
626:
624:
621:
620:
615:
612:
606:
592:
588:
577:
573:
544:
540:
533:
529:
520:
516:
515:
513:
504:
500:
498:
495:
494:
490:
473:
448:
417:thermal runaway
412:
405:
398:
383:
375:
354:
324:
317:
310:
294:quiescent point
286:operating point
275:current mirrors
269:, for example,
236:
225:
224:
223:
218:
207:
201:
198:
188:Please help to
187:
171:
167:
156:
145:
139:
136:
93:
91:
81:
69:
28:
24:
17:
12:
11:
5:
4843:
4833:
4832:
4818:
4817:
4812:
4804:
4803:External links
4801:
4799:
4798:
4788:
4786:
4783:
4781:
4780:
4773:
4747:
4725:
4723:
4720:
4719:
4718:
4713:
4708:
4703:
4696:
4693:
4675:common emitter
4667:
4643:
4639:
4627:
4624:
4622:
4619:
4618:
4617:
4611:Disadvantages:
4608:
4607:
4603:
4602:
4590:
4586:
4576:
4572:
4563:
4542:
4508:
4497:
4493:
4484:
4477:
4468:
4455:
4448:
4444:
4440:
4428:
4425:
4424:
4423:
4417:Disadvantages:
4414:
4413:
4395:
4390:
4380:
4367:
4366:
4353:
4349:
4345:
4333:
4330:
4321:
4320:
4316:
4313:
4312:
4311:
4307:
4303:
4299:
4295:
4291:
4287:
4283:
4279:
4275:
4271:
4268:
4264:
4260:
4253:
4249:
4245:
4241:
4240:
4236:
4232:
4224:
4220:
4206:
4202:
4198:
4193:
4189:
4185:
4176:
4172:
4169:
4166:
4163:
4160:
4140:
4129:
4118:
4114:
4106:
4102:
4097:
4091:
4087:
4083:
4080:
4070:
4061:
4053:
4049:
4045:
4040:
4036:
4032:
4023:
4019:
4016:
4013:
4010:
4007:
3996:
3992:
3984:
3980:
3975:
3969:
3965:
3961:
3958:
3948:
3939:
3936:
3927:
3923:
3920:
3911:
3898:
3892:Disadvantages:
3889:
3888:
3885:
3862:
3858:
3854:
3849:
3845:
3841:
3832:
3828:
3825:
3822:
3819:
3816:
3805:
3801:
3793:
3789:
3784:
3778:
3774:
3770:
3767:
3757:
3748:
3739:
3718:
3709:
3699:
3695:
3686:
3682:
3673:
3669:
3660:
3656:
3647:
3621:
3617:
3612:
3602:
3598:
3593:
3589:
3585:
3576:
3552:
3547:
3543:
3539:
3534:
3530:
3526:
3520:
3516:
3504:
3500:
3494:
3489:
3485:
3481:
3476:
3472:
3468:
3461:
3457:
3451:
3447:
3434:
3430:
3424:
3419:
3415:
3411:
3406:
3402:
3398:
3392:
3388:
3376:
3372:
3363:
3337:
3333:
3306:
3287:
3283:
3279:
3275:
3271:
3256:
3253:
3240:
3239:
3235:
3232:
3231:
3230:
3226:
3223:
3219:
3215:
3208:
3204:
3200:
3199:
3188:
3179:
3175:
3166:
3162:
3159:
3156:
3153:
3150:
3122:
3117:
3108:
3104:
3095:
3091:
3085:
3073:
3069:
3066:
3063:
3060:
3057:
3054:
3045:
3039:
3030:
3026:
3017:
3013:
3010:
3004:
2995:
2991:
2988:
2979:
2966:
2960:Disadvantages:
2931:
2927:
2924:
2921:
2918:
2915:
2912:
2903:
2891:
2887:
2878:
2871:
2862:
2843:
2836:
2832:
2828:
2824:
2820:
2816:
2812:
2808:
2804:
2800:
2780:
2768:
2763:
2757:
2748:
2717:
2713:
2704:
2694:
2690:
2681:
2677:
2666:
2661:
2632:
2629:
2621:
2620:
2589:
2576:
2575:
2557:
2545:
2527:
2500:
2487:
2486:
2468:
2441:
2420:
2409:
2398:
2389:
2385:
2376:
2372:
2344:
2339:
2330:
2326:
2317:
2313:
2307:
2295:
2291:
2288:
2279:
2275:
2266:
2260:
2251:
2247:
2238:
2234:
2231:
2225:
2216:
2212:
2209:
2200:
2179:
2153:
2140:
2139:
2121:
2106:Disadvantages:
2103:
2102:
2084:
2057:
2045:
2018:
1991:
1964:
1928:
1901:
1874:
1847:
1820:
1808:
1807:
1787:
1783:
1780:
1777:
1774:
1771:
1768:
1759:
1747:
1743:
1734:
1727:
1718:
1688:
1676:
1675:
1664:
1655:
1651:
1642:
1638:
1635:
1632:
1629:
1626:
1617:
1613:
1604:
1600:
1580:
1573:
1563:
1553:
1519:
1514:
1495:
1491:
1482:
1466:
1465:
1454:
1445:
1441:
1432:
1428:
1425:
1422:
1419:
1416:
1407:
1403:
1394:
1390:
1381:
1377:
1368:
1364:
1355:
1351:
1340:
1333:
1323:
1319:
1312:
1309:
1300:
1296:
1278:
1248:
1244:
1241:
1232:
1216:
1215:
1204:
1191:
1182:
1172:
1158:
1146:
1136:
1132:
1123:
1119:
1110:
1106:
1096:
1086:
1082:
1064:
1034:
998:
988:, the voltage
964:
937:
910:
881:
878:
864:
863:
844:
837:Disadvantages:
834:
833:
820:
816:
804:
795:
788:
779:
775:
755:
744:
734:
729:
720:
716:
707:
694:
682:
672:
668:
665:
656:
629:
610:
590:
586:
583:voltage source
575:
571:
555:
543:
532:
528:
519:
512:
503:
472:
469:
468:
467:
464:
461:
458:
455:
447:
444:
443:
442:
434:
428:
410:
403:
396:
381:
374:
371:
353:
350:
345:
344:
341:
338:
331:
323:
320:
315:
308:
238:
237:
220:
219:
174:
172:
165:
158:
157:
72:
70:
63:
58:
32:
31:
29:
22:
15:
9:
6:
4:
3:
2:
4842:
4831:
4828:
4827:
4825:
4816:
4813:
4810:
4807:
4806:
4795:
4790:
4789:
4776:
4774:0-19-514251-9
4770:
4766:
4761:
4760:
4751:
4744:
4743:0-521-37095-7
4740:
4736:
4730:
4726:
4717:
4714:
4712:
4709:
4707:
4704:
4702:
4699:
4698:
4692:
4688:
4684:
4681:
4676:
4665:
4661:
4659:
4636:
4632:
4615:
4614:
4613:
4612:
4605:
4604:
4588:
4584:
4574:
4570:
4561:
4540:
4532:
4531:
4530:
4529:
4506:
4495:
4491:
4482:
4475:
4466:
4452:
4433:
4421:
4420:
4419:
4418:
4393:
4388:
4378:
4369:
4368:
4364:
4363:
4362:
4361:
4357:
4338:
4329:
4326:
4325:
4314:
4269:
4258:
4257:
4243:
4242:
4230:
4204:
4200:
4196:
4191:
4187:
4183:
4174:
4167:
4164:
4161:
4138:
4127:
4116:
4112:
4104:
4100:
4095:
4089:
4085:
4081:
4078:
4068:
4059:
4051:
4047:
4043:
4038:
4034:
4030:
4021:
4014:
4011:
4008:
3994:
3990:
3982:
3978:
3973:
3967:
3963:
3959:
3956:
3946:
3937:
3934:
3925:
3921:
3918:
3909:
3896:
3895:
3894:
3893:
3886:
3883:
3882:
3881:
3880:
3860:
3856:
3852:
3847:
3843:
3839:
3830:
3823:
3820:
3817:
3803:
3799:
3791:
3787:
3782:
3776:
3772:
3768:
3765:
3755:
3746:
3737:
3716:
3707:
3697:
3693:
3684:
3680:
3671:
3667:
3658:
3654:
3645:
3635:
3619:
3615:
3610:
3600:
3596:
3591:
3587:
3583:
3574:
3545:
3541:
3537:
3532:
3528:
3518:
3514:
3502:
3498:
3487:
3483:
3479:
3474:
3470:
3459:
3455:
3449:
3445:
3432:
3428:
3417:
3413:
3409:
3404:
3400:
3390:
3386:
3374:
3370:
3361:
3335:
3331:
3304:
3294:
3291:
3269:
3261:
3252:
3249:
3245:
3244:
3233:
3224:
3213:
3212:
3202:
3201:
3186:
3177:
3173:
3164:
3157:
3154:
3151:
3120:
3106:
3102:
3093:
3083:
3071:
3064:
3061:
3058:
3052:
3043:
3028:
3024:
3015:
3008:
3002:
2993:
2989:
2986:
2977:
2964:
2963:
2962:
2961:
2957:
2954:
2953:
2929:
2922:
2919:
2916:
2910:
2901:
2889:
2885:
2876:
2869:
2860:
2850:
2847:
2840:
2778:
2766:
2761:
2755:
2746:
2737:
2715:
2711:
2702:
2692:
2688:
2679:
2675:
2664:
2659:
2650:
2646:
2637:
2628:
2625:
2617:
2613:
2609:
2587:
2579:The resistor
2578:
2577:
2555:
2546:
2525:
2498:
2489:
2488:
2466:
2439:
2418:
2410:
2396:
2387:
2383:
2374:
2370:
2342:
2328:
2324:
2315:
2305:
2293:
2289:
2286:
2277:
2273:
2264:
2249:
2245:
2236:
2229:
2223:
2214:
2210:
2207:
2198:
2177:
2151:
2142:
2141:
2119:
2110:
2109:
2108:
2107:
2082:
2055:
2046:
2043:
2042:
2041:
2040:
2036:
2016:
1989:
1962:
1926:
1899:
1872:
1845:
1818:
1785:
1778:
1775:
1772:
1766:
1757:
1745:
1741:
1732:
1725:
1716:
1708:
1707:
1706:
1686:
1662:
1653:
1649:
1640:
1633:
1630:
1627:
1615:
1611:
1602:
1598:
1578:
1571:
1561:
1551:
1539:
1538:
1537:
1517:
1512:
1493:
1489:
1480:
1471:
1452:
1443:
1439:
1430:
1423:
1420:
1417:
1405:
1401:
1392:
1388:
1379:
1375:
1366:
1353:
1349:
1338:
1331:
1321:
1317:
1307:
1298:
1294:
1276:
1268:
1267:
1266:
1246:
1242:
1239:
1230:
1221:
1202:
1189:
1180:
1170:
1156:
1144:
1134:
1121:
1117:
1108:
1094:
1084:
1080:
1062:
1054:
1053:
1052:
1032:
996:
987:
982:
962:
935:
908:
899:
895:
886:
877:
875:
869:
868:
861:
857:
853:
849:
845:
841:
840:
839:
838:
831:
830:
829:
828:
824:
793:
786:
777:
753:
742:
732:
727:
718:
714:
705:
680:
670:
666:
663:
654:
627:
618:
609:
603:
598:
596:
584:
581:
569:
553:
541:
530:
526:
517:
510:
501:
491:
488:
486:
477:
465:
462:
459:
456:
453:
452:
451:
440:
435:
432:
429:
426:
423:
422:
421:
419:
418:
409:
402:
395:
391:
387:
380:
370:
367:
365:
364:
359:
349:
342:
339:
336:
332:
329:
328:
327:
319:
314:
307:
303:
299:
295:
291:
287:
282:
280:
276:
272:
268:
264:
260:
256:
249:
244:
234:
231:
216:
213:
205:
195:
191:
185:
184:
178:
173:
164:
163:
154:
151:
143:
132:
129:
125:
122:
118:
115:
111:
108:
104:
101: –
100:
96:
95:Find sources:
89:
85:
79:
78:
73:This article
71:
67:
62:
61:
56:
54:
47:
46:
41:
40:
35:
30:
21:
20:
4793:
4758:
4750:
4734:
4729:
4689:
4685:
4672:
4629:
4610:
4609:
4527:
4453:
4438:
4435:Emitter bias
4427:Emitter bias
4416:
4415:
4359:
4358:
4343:
4327:
4323:
4322:
4282:is low, or R
4227:denotes the
3891:
3890:
3878:
3636:
3295:
3292:
3267:
3266:
3250:
3246:
3242:
3241:
2959:
2958:
2955:
2951:
2851:
2848:
2841:
2642:
2623:
2622:
2612:voltage gain
2105:
2104:
2038:
2037:
1809:
1677:
1467:
1217:
983:
891:
870:
866:
865:
843:temperature.
836:
835:
826:
825:
614:
605:
599:
594:
492:
489:
484:
482:
466:Emitter bias
449:
438:
415:
407:
400:
393:
385:
378:
376:
368:
361:
355:
346:
335:Early effect
325:
312:
305:
297:
293:
289:
283:
253:
226:
208:
199:
180:
146:
137:
127:
120:
113:
106:
94:
82:Please help
77:verification
74:
50:
43:
37:
36:Please help
33:
4745:, pp. 73-75
4528:Advantages:
4360:Advantages:
4294:closer to V
3879:Advantages:
3353:is given by
2952:Advantages:
2039:Advantages:
896:to prevent
827:Advantages:
363:active mode
333:Due to the
194:introducing
4722:References
4256:very low.
3211:very low.
2606:causes an
595:fixed bias
454:Fixed bias
431:Heat sinks
290:bias point
202:April 2024
177:references
140:April 2024
110:newspapers
39:improve it
4646:is about
4589:β
4571:≫
4541:β
4492:−
4197:∥
4162:β
4113:−
4060:≈
4044:∥
4009:β
3991:−
3938:β
3922:β
3853:∥
3818:β
3800:−
3566:provided
3499:≈
3429:−
3323:, across
3174:≫
3152:β
3103:−
3084:≈
3059:β
3025:−
3009:β
2990:β
2917:β
2886:−
2736:Ohm's law
2712:−
2689:−
2485:very low.
2419:β
2384:≫
2371:β
2325:−
2306:≈
2290:β
2246:−
2230:β
2211:β
2178:β
1773:β
1742:−
1650:−
1628:β
1612:−
1572:⏞
1536:, and so
1470:Ohm's law
1440:−
1418:β
1402:−
1376:−
1332:⏞
1318:β
1308:−
1265:, and so
1243:β
1190:⏞
1171:−
1145:⏞
1095:−
728:−
667:β
527:−
386:decreases
263:resistors
248:load line
45:talk page
4824:Category
4695:See also
4673:Q3 is a
4306:lowers V
4290:raises V
4184:>>
3584:<<
646:as well:
578:and the
4651:⁄
4631:Class B
4219:where R
2619:points.
2616:Q-point
1218:By the
298:Q-point
190:improve
124:scholar
4771:
4741:
4716:MOSFET
4680:diodes
4324:Usage:
3341:
3243:Usage:
2624:Usage:
867:Usage:
790:
259:biased
179:, but
126:
119:
112:
105:
97:
4274:|| R
4235:and R
3286:and R
3274:and R
2835:= α I
2827:= β I
2734:From
1468:From
984:From
819:and R
693:Now V
296:, or
131:JSTOR
117:books
4809:Bias
4769:ISBN
4739:ISBN
4633:and
4454:If R
4270:If R
4259:If R
4231:of R
4223:|| R
3225:If R
3214:If R
600:The
566:For
284:The
273:and
103:news
4765:397
4553:if
4252:||R
2811:= I
2547:If
2490:If
2411:As
1810:If
1705:is
1051:is
613:or
570:, V
86:by
4826::
4635:AB
4500:be
4487:ee
4449:cc
4441:ee
4308:be
4265:cc
4121:be
4073:cc
3999:be
3951:cc
3808:be
3760:cc
3689:be
3663:be
3634:.
3507:cc
3379:cc
3220:cc
3111:be
3098:cc
3033:be
3020:cc
2894:be
2881:cc
2821:Rb
2801:be
2720:be
2684:cc
2608:AC
2530:cc
2333:be
2320:cc
2254:be
2241:cc
2087:cc
2060:cc
1823:be
1750:be
1737:cc
1658:be
1607:cc
1448:be
1397:cc
1384:be
1303:cc
1222:,
1185:be
1089:cc
940:cc
823:.
782:ce
723:cc
710:ce
695:ce
611:FE
597:.
587:cc
580:DC
572:be
535:be
522:cc
487:.
397:BE
382:BE
309:ce
302:DC
292:,
281:.
246:A
48:.
4777:.
4653:4
4649:1
4644:c
4640:c
4638:I
4601:.
4585:/
4579:b
4575:R
4566:e
4562:R
4511:e
4507:R
4496:V
4483:V
4476:=
4471:e
4467:I
4456:b
4445:e
4398:e
4394:R
4389:/
4383:c
4379:R
4354:e
4350:e
4346:e
4317:e
4304:2
4300:c
4296:c
4292:b
4288:1
4284:2
4280:1
4276:2
4272:1
4261:e
4254:2
4250:1
4246:e
4237:2
4233:1
4225:2
4221:1
4205:2
4201:R
4192:1
4188:R
4179:e
4175:R
4171:)
4168:1
4165:+
4159:(
4139:,
4132:e
4128:R
4117:V
4105:2
4101:R
4096:/
4090:1
4086:R
4082:+
4079:1
4069:V
4052:2
4048:R
4039:1
4035:R
4031:+
4026:e
4022:R
4018:)
4015:1
4012:+
4006:(
3995:V
3983:2
3979:R
3974:/
3968:1
3964:R
3960:+
3957:1
3947:V
3935:=
3930:b
3926:I
3919:=
3914:c
3910:I
3899:c
3861:2
3857:R
3848:1
3844:R
3840:+
3835:e
3831:R
3827:)
3824:1
3821:+
3815:(
3804:V
3792:2
3788:R
3783:/
3777:1
3773:R
3769:+
3766:1
3756:V
3747:=
3742:b
3738:I
3717:.
3712:e
3708:R
3702:e
3698:I
3694:+
3685:V
3681:=
3676:e
3672:V
3668:+
3659:V
3655:=
3650:b
3646:V
3620:1
3616:R
3611:/
3605:b
3601:V
3597:=
3592:1
3588:I
3579:b
3575:I
3551:)
3546:2
3542:R
3538:+
3533:1
3529:R
3525:(
3519:2
3515:R
3503:V
3493:)
3488:2
3484:R
3480:+
3475:1
3471:R
3467:(
3460:2
3456:R
3450:1
3446:R
3437:b
3433:I
3423:)
3418:2
3414:R
3410:+
3405:1
3401:R
3397:(
3391:2
3387:R
3375:V
3371:=
3366:b
3362:V
3336:2
3332:R
3309:b
3305:V
3288:2
3284:1
3280:2
3276:2
3272:1
3270:R
3236:e
3227:b
3216:e
3209:b
3205:e
3187:.
3182:b
3178:R
3169:e
3165:R
3161:)
3158:1
3155:+
3149:(
3125:e
3121:R
3116:)
3107:V
3094:V
3090:(
3076:e
3072:R
3068:)
3065:1
3062:+
3056:(
3053:+
3048:b
3044:R
3038:)
3029:V
3016:V
3012:(
3003:=
2998:b
2994:I
2987:=
2982:c
2978:I
2967:c
2934:e
2930:R
2926:)
2923:1
2920:+
2914:(
2911:+
2906:b
2902:R
2890:V
2877:V
2870:=
2865:b
2861:I
2844:c
2837:e
2833:c
2829:b
2825:c
2817:e
2815:R
2813:e
2809:e
2805:e
2783:b
2779:R
2771:b
2767:R
2762:V
2756:=
2751:b
2747:I
2716:V
2707:e
2703:R
2697:e
2693:I
2680:V
2676:=
2669:b
2665:R
2660:V
2592:b
2588:R
2560:b
2556:R
2526:V
2503:c
2499:R
2471:b
2467:R
2444:c
2440:R
2397:.
2392:b
2388:R
2379:c
2375:R
2347:c
2343:R
2338:)
2329:V
2316:V
2312:(
2298:c
2294:R
2287:+
2282:c
2278:R
2274:+
2269:b
2265:R
2259:)
2250:V
2237:V
2233:(
2224:=
2219:b
2215:I
2208:=
2203:c
2199:I
2156:c
2152:I
2124:b
2120:R
2101:.
2083:V
2056:V
2021:c
2017:I
1994:b
1990:I
1967:b
1963:R
1938:b
1933:R
1927:V
1904:c
1900:R
1877:c
1873:I
1850:c
1846:I
1819:V
1790:c
1786:R
1782:)
1779:1
1776:+
1770:(
1767:+
1762:b
1758:R
1746:V
1733:V
1726:=
1721:b
1717:I
1691:b
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1663:.
1654:V
1645:c
1641:R
1637:)
1634:1
1631:+
1625:(
1620:b
1616:I
1603:V
1599:=
1590:b
1585:R
1579:V
1566:b
1562:R
1556:b
1552:I
1522:b
1518:R
1513:/
1505:b
1500:R
1494:V
1490:=
1485:b
1481:I
1453:.
1444:V
1435:c
1431:R
1427:)
1424:1
1421:+
1415:(
1410:b
1406:I
1393:V
1389:=
1380:V
1371:c
1367:R
1363:)
1358:b
1354:I
1350:+
1343:c
1339:I
1326:b
1322:I
1311:(
1299:V
1295:=
1288:b
1283:R
1277:V
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1247:I
1240:=
1235:c
1231:I
1203:.
1181:V
1161:c
1157:R
1139:c
1135:R
1131:)
1126:b
1122:I
1118:+
1113:c
1109:I
1105:(
1085:V
1081:=
1074:b
1069:R
1063:V
1037:b
1033:R
1008:b
1003:R
997:V
967:c
963:R
936:V
913:b
909:R
821:c
817:b
803:)
798:c
794:I
787:,
778:V
774:(
754:.
747:c
743:R
737:c
733:I
719:V
715:=
706:V
681:.
675:b
671:I
664:=
659:c
655:I
632:c
628:I
616:β
607:h
591:b
585:V
576:b
554:.
546:b
542:R
531:V
518:V
511:=
506:b
502:I
411:C
408:I
404:B
401:I
394:V
379:V
316:c
313:I
306:V
279:β
233:)
227:(
215:)
209:(
204:)
200:(
186:.
153:)
147:(
142:)
138:(
128:·
121:·
114:·
107:·
80:.
55:)
51:(
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