Bipolar transistor parameter symbols and their meanings

Bipolar transistors have many parameter symbols and their meanings. For example, B, C, and E represent the base, collector, and emitter respectively. Ib, Ic, and Ie represent the currents of the base, collector, and emitter, respectively, while Vcb, Vbe , Vce represents the voltage between the collector and the base, the emitter and the base, and the collector and the emitter.

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Together, these parameter symbols define the operating characteristics of a bipolar transistor and are critical to understanding its performance and how it is used.

Bipolar transistor is a common electronic device. Its parameter symbols and their meanings are as follows:

Ic: collector current, refers to the DC current passing through the collector of the transistor under given conditions. The average value of collector DC or AC current.
Icbo: The reverse saturation current between the base and collector when the emitter is open circuit. The base is grounded, the emitter is open to ground, and the reverse cut-off current between the collector and the base under the specified VCB reverse voltage condition
Iceo: The reverse blocking current between the emitter and collector when the base is open circuit at a given temperature. The emitter is connected to ground and the base is open to ground. Under the specified reverse voltage VCE condition, the reverse cut-off current between the collector and emitter is reached.

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Iebo: Reverse cutoff current between base and emitter when collector is open circuit at a given temperature. The base is grounded, the collector is open to ground, and under the specified reverse voltage VEB condition, the reverse cut-off current between the emitter and the base is reached.
IB: The average value of base DC current or AC current
IE: the average value of the emitter DC current or AC current
Icer: The series resistor R between the base and the emitter. When the voltage VCE between the collector and the emitter is a specified value, the reverse cut-off current between the collector and the emitter is
Ices: The emitter is grounded, the base is short-circuited to ground, and under the specified reverse voltage VCE condition, the reverse cut-off current between the collector and the emitter
Icex: The emitter is grounded, a specified bias voltage is applied between the base and the emitter, and under the specified reverse bias voltage VCE, the reverse cut-off current between the collector and the emitter
ICM: The maximum allowable current of the collector or the maximum average value of the AC current.
IBM: The maximum value of DC current that can continuously pass through the base within the range that the collector is allowed to dissipate power, or the maximum average value of AC current
ICMP: collector maximum allowable pulse current
ISB: secondary breakdown current
IAGC: forward automatic current control
Pc: collector dissipation power, which refers to the maximum power that the transistor can withstand during normal operation.
PCM: The maximum allowable power dissipation of the collector refers to the maximum power dissipation that the transistor can withstand under given conditions.
Pi: input power
Po: output power
Posc: oscillation power
Pn: noise power
Ptot: total power dissipated
VCB: Reverse breakdown voltage between collector and base.
VBE (Vb): forward voltage between base and emitter.
VCEO: Reverse breakdown voltage between collector and emitter.
VCES: Saturation voltage between collector and emitter.
β: Common base amplification factor, which refers to the ratio of the change of the output signal to the change of the input signal in the common base circuit.
α: Common emitter amplification factor, which refers to the ratio of the change amount of the output signal to the change amount of the input signal in the common emitter circuit.
fT: Characteristic frequency of the transistor, which refers to the highest operating frequency of the transistor.
fmax: The limit frequency of the transistor, which refers to the highest frequency at which the transistor can operate normally. The operating frequency when the triode power gain is equal to 1.
fmin: The lowest operating frequency of the transistor, which refers to the lowest frequency at which the transistor can operate normally.
fα: Common emitter cutoff frequency, which refers to the frequency point at which the amplification factor begins to decrease when the frequency of the input signal increases in the common emitter circuit.
fβ: The turning frequency of the frequency response of the common emitter signal source, which refers to the frequency point at which the amplification factor begins to decrease when the frequency of the input signal increases in the common emitter circuit.
fH: Common base cutoff frequency, which refers to the frequency point at which the amplification factor begins to decrease when the frequency of the input signal increases in the common base circuit.
fL: The turning frequency of the frequency response of the common base signal source, which refers to the frequency point at which the amplification factor begins to decrease when the frequency of the input signal increases in the common base circuit.
Vf: forward voltage drop, refers to the forward conduction voltage of the transistor.
Vr: Reverse voltage drop, refers to the reverse conduction voltage of the transistor.
VCB: collector-base (DC) voltage
VCE: collector-emitter (DC) voltage
VBE: Base-emitter (DC) voltage

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VCBO: The base is grounded, the emitter is open to ground, and the maximum withstand voltage between the collector and the base under specified conditions
VEBO: The base is grounded, the collector is open to ground, and the maximum withstand voltage between the emitter and the base under specified conditions
VCEO: The emitter is grounded, the base is open to ground, and the maximum withstand voltage between the collector and emitter under specified conditions
VCER: The emitter is grounded, a resistor R is connected in series between the base and the emitter, and the maximum withstand voltage between the collector and the emitter under specified conditions
VCES: The emitter is grounded, the base is short-circuited to ground, and the maximum withstand voltage between the collector and emitter under specified conditions
VCEX: The emitter is grounded, a specified bias voltage is applied between the base and the emitter, and the maximum withstand voltage between the collector and the emitter under specified conditions
Vp: punch-through voltage.
VSB: Secondary breakdown voltage
VBB: Base (DC) power supply voltage (external circuit parameters)
Vcc: Collector (DC) power supply voltage (external circuit parameters)
VEE: Emitter (DC) power supply voltage (external circuit parameters)
VCE(sat): The emitter is grounded, and the saturation voltage drop between the collector and the emitter under Ic and IB conditions is specified.
VBE(sat): The emitter is grounded, and under specified Ic and IB conditions, the base-emitter saturation voltage drop (forward voltage drop)
VAGC: forward automatic gain control voltage
Vn(p-p): Peak equivalent noise voltage at the input end
V n: noise voltage
D: duty cycle
Bvceo: Reverse breakdown voltage, which refers to the maximum reverse voltage between the base and collector of a transistor during normal operation.
BVcbo: open emitter, breakdown voltage between collector and base
Bvbeo: Forward breakdown voltage refers to the maximum forward voltage between the base and emitter of a transistor during normal operation.
Bvces: saturation voltage drop, refers to the voltage drop between the base and emitter of the transistor when it is in saturation state. Base and emitter short circuit CE junction breakdown voltage.
BVebo: Open collector EB junction breakdown voltage.
BV cer: The base and emitter are connected in series with a resistor, CE junction breakdown voltage.
αF: forward current amplification factor, refers to the forward current amplification coefficient of the transistor.
αR: Reverse current amplification factor, which refers to the reverse current amplification coefficient of the transistor.
fmaxF: forward maximum operating frequency, refers to the upper limit of the forward operating frequency of the transistor.
fmaxR: reverse maximum operating frequency, which refers to the upper limit of the reverse operating frequency of the transistor.
fminF: forward minimum operating frequency, refers to the lower limit of the forward operating frequency of the transistor.
fminR: Reverse minimum operating frequency, which refers to the lower limit of the reverse operating voltage of the transistor.
Cc: collector capacitance
Ccb: Capacitance between collector and base
Cce: emitter ground output capacitance
Ci: input capacitance
Cib: common base input capacitance
Cie: common emitter input capacitance
Cies: common-emitter short-circuit input capacitance
Cieo: Common emitter open input capacitance
Cn: Neutralizing capacitor (external circuit parameters)
Co: zero bias capacitor
Cob: common base output capacitor. In the base circuit, the output capacitance between the collector and the base
Coe: common emitter output capacitance
Coeo: Common emitter open output capacitor
Cre: common emitter feedback capacitor
Cic: collector junction barrier capacitance
CL: Load capacitance (external circuit parameters)
Cp: parallel capacitance (external circuit parameters)
Cj: Junction (interelectrode) capacitance, indicating the total capacitance of the germanium detection diode when a specified bias voltage is applied to both ends of the diode.
Cjv: bias junction capacitance
Cjo: zero bias junction capacitance
Cjo/Cjn: junction capacitance change
Cs: case capacitance or package capacitance
Ct: total capacitance
CTV: voltage temperature coefficient. The ratio of the relative change of the stable voltage to the absolute change of the ambient temperature under the test current
CTC: Capacitance temperature coefficient
Cvn: nominal capacitance
hFE: common emitter quiescent current amplification factor
hIE: common emitter static input impedance
hOE: common emitter static output conductance
h RE: Common emitter static voltage feedback coefficient
hie: total emission of very small signal short-circuit input impedance
hre: total emission of very small signal open circuit voltage feedback coefficient
hfe: total emission of very small signal short-circuit voltage amplification factor
hoe: total emission of very small signal open circuit output admittance
ESB: Second breakdown energy
rbb: base area extended resistance (base area intrinsic resistance)
rbbCc: base-collector time constant, which is the product of base extension resistance and collector junction capacitance
rie: input resistance when the emitter is grounded and the AC output is short-circuited
roe: The output resistance when the emitter is grounded and the AC input is short-circuited when measured under specified VCE, Ic or IE, and frequency conditions.
RE: External emitter resistor (external circuit parameters)
RB: External base resistor (external circuit parameters)
Rc: external collector resistor (external circuit parameters)
RBE: External base-emitter resistance (external circuit parameters)
RL: Load resistance (external circuit parameters)
RG: signal source internal resistance
Rth: thermal resistance
Ta: ambient temperature
Tc: shell temperature
Ts: junction temperature
Tjm: maximum allowable junction temperature
Tstg: storage temperature
td: delay time
tr: rise time
ts: storage time
tf: fall time
ton: opening time
toff: off time
IF: Forward DC current (forward test current). The current passing through the inter-electrode of the germanium detection diode under the specified forward voltage VF; the maximum operating current (average value) allowed to pass continuously in the sinusoidal half-wave of the silicon rectifier and silicon stack under the specified conditions of use, and the silicon switch The maximum forward DC current allowed to pass through the diode under rated power; the current given when measuring the forward electrical parameters of the Zener diode.
IF (AV): forward average current
IFM (IM): Forward peak current (forward maximum current). The maximum forward pulse current allowed through the diode at rated power. LED limits.

What are the application scenarios of bipolar transistors?

The application scenarios of bipolar transistors mainly include the following aspects:
In the fields of radio, television, communications, radar, computers, automatic control devices, electronic instruments, household appliances, etc., used for amplification, oscillation, switching and other functions.
Traditional industries such as industry, communications, computers, consumer electronics, automotive electronics, aerospace, national defense and military industries, as well as emerging industries such as rail transit, new energy, smart grids, and new energy vehicles.
Constitute amplifier circuits, or drive speakers, motors and other equipment, and are widely used in aerospace engineering, medical equipment, robots and other application products.
As a key component of amplifiers in audio amplification, radio frequency amplification, video amplification and other fields.

What are the disadvantages of bipolar transistors?

Disadvantages of bipolar transistors include temperature sensitivity and bias, which can cause circuit instability. In addition, bipolar transistors may introduce noise that affects circuit performance. In high-speed switching circuits, the response speed of bipolar transistors is relatively slow and is not as stable as field effect transistors. In addition, bipolar transistors consume large amounts of power, require large drive currents, and are relatively large in size.
Despite these shortcomings, bipolar transistors are still used in many fields because of their advantages such as fast response speed, high amplification, and low noise. Choosing the right transistor based on specific needs can improve the performance and stability of your circuit.

What is the meaning of collector current Ic, Ice, Ie?

The collector currents Ic, Ice, and Ie have the following meanings:
Ic is the limit value, which refers to the collector current, and C represents the collector. The specific meaning of Ic is the maximum DC current of the collector.
Iceo, ICES, and ICER are called transistor collector reverse current. Their names and meanings are as follows: When the emitter is open and a reverse voltage is applied between the collector and the base, the reverse current of the collector is usually called the reverse current. towards saturation current.
Ie represents the current at the emission extreme.
In addition, the transistor has three ports, E emitter, B base and C collector, and I represents the current, IE represents the current at the emitter terminal, IB represents the current at the base terminal, and IC represents the current at the collector terminal.

What are the applications of bipolar transistors?

Bipolar transistors have a wide range of applications, mainly including the following aspects:
Communication field: Bipolar transistors are used for signal amplification, oscillation, switching, etc., and are widely used in radio, television, communications, radar and other fields.
Industrial control field: As a key electronic device, bipolar transistors are used to realize amplification, switching, isolation and other functions of control circuits, and are widely used in industrial automation control systems.
Consumer electronics: Bipolar transistors are used in audio amplification, video amplification, switching circuits, etc., and are key components in many electronic products.
Automotive electronics: Bipolar transistors are used in automotive sensors, ignitions, lighting control and other circuits to function as signal amplification and switching.
Aerospace field: Bipolar transistors have the characteristics of high reliability and long life, and are suitable for various electronic equipment in aerospace engineering.
Medical device field: Bipolar transistors are used in sensors, amplifiers and other circuits in medical devices to perform signal processing and amplification.
Robot field: Bipolar transistors are used in robot control systems and sensor circuits to achieve signal amplification and processing.
Bipolar transistors have a wide range of applications, covering communications, industrial control, consumer electronics, automotive electronics, aerospace, medical equipment and robotics.