SEMICONDUCTOR JUNCTION NOISE REVISITED: WHERE HAVE ALL THE PHYSICAL NOISE SOURCES GONE?

2001 ◽  
Vol 01 (03) ◽  
pp. C15-C19 ◽  
Author(s):  
PAUL J. EDWARDS

The distinction between "physical" and "equivalent" noise sources in bipolar junction transistors and other semiconductor devices has become blurred in the current engineering textbooks. An unfortunate consequence of this is the emergence in the literature of fictitious noise sources such as the "the collector-current shot noise" and the "base-current shot noise". These are often assigned a physical reality and incorrectly treated as real physical noise sources, independent of circuit topology. Text-books have encouraged successive generations of students in this belief. Non-physical noise sources such as these are convenient and legitimate, even essential, for the effective modeling and simulation of circuit noise. However their naïve use in teaching and research is likely to continue to give rise to fallacious concepts and misleading conclusions. The physical. The physical modeling of the light-emitting diode, the photon transport transistor and the bipolar junction transistor are briefly discussed to illustrate this view.

2021 ◽  
Author(s):  
Sara Sharifian Attar

The goal of this research was to develop a capability for the electrothermal modeling of electronic circuits. The objective of the thermal modeling process was to create a model that represents the thermal behavior of the physical system. The project focuses on electrothermal analysis at devices and chip level. A novel method to perform electrothermal analysis of integrated circuits based on the relaxation approach is proposed in this research. An interface program couples a circuit simulator and a thermal simulator. The developed simulator is capable of performing both steady state and transient analaysis at devices and chip level. The proposed method was applied to perform electrothermal analysis of Silicon Bipolar Junction Transistor (BJT) to predict the temperature distribution and the device performance in a circuit. Thermal nonlinearity due to temperature-dependent material parameters in the context of thermal modeling of the device and circuit has also been considered. The DC characteristics of the device were investigated. The obtained results indicate that the operating point of the device varies while the device reaches its junction temperature. The accuracy of the electrothermal simulator has been evaluated for steady state analysis. The experimental results of a BJT amplifier were compared to the simulator results of the similar circuit. The electrothermal simulation results of BJT amplifier circuit indicate a good agreement with the available experimental results in terms of power dissipation, collector current and base-emitter voltage. The performance of the electrothermal simulator has been evaluated for tansient analysis. A current mirror circuit using Si NPN BJTs was simulated. According to the electrical simulator, the output current follows the reference current immediately. Nonetheless, the electrothermal simulator results depict that the load current has delay to reach a constant value which is not the same as the reference current, due to the influence of thermal coupling and self heating. The obtained results are in agreement with the available results in literature.


2005 ◽  
Vol 483-485 ◽  
pp. 901-904 ◽  
Author(s):  
Sumi Krishnaswami ◽  
Anant K. Agarwal ◽  
Craig Capell ◽  
Jim Richmond ◽  
Sei Hyung Ryu ◽  
...  

1000 V Bipolar Junction Transistor and integrated Darlington pairs with high current gain have been developed in 4H-SiC. The 3.38 mm x 3.38 mm BJT devices with an active area of 3 mm x 3 mm showed a forward on-current of 30 A, which corresponds to a current density of 333 A/cm2, at a forward voltage drop of 2 V. A common-emitter current gain of 40 was measured on these devices. A specific on-resistance of 6.0 mW-cm2 was observed at room temperature. The onresistance increases at higher temperatures, while the current gain decreases to 30 at 275°C. In addition, an integrated Darlington pair with an active area of 3 mm x 3 mm showed a collector current of 30 A at a forward drop of 4 V at room temperature. A current gain of 2400 was measured on these devices. A BVCEO of 1000 V was measured on both of these devices.


2006 ◽  
Vol 527-529 ◽  
pp. 1417-1420 ◽  
Author(s):  
Jian Hui Zhang ◽  
Jian Wu ◽  
Petre Alexandrov ◽  
Terry Burke ◽  
Kuang Sheng ◽  
...  

This paper reports recent progress in the development of high power 4H-SiC BJTs based on an improved device design and fabrication scheme. Near theoretical limit high blocking voltage of VCEO=1,836 V has been achieved for 4H-SiC BJTs based on a drift layer of only 12 μm, doped to 6.7x1015 cm-3. The collector current measured for a single cell BJT with an active area of 0.61 mm2 is up to IC=9.87 A (JC=1618 A/cm2). The collector current is 7.64 A (JC=1252 A/cm2) at VCE=5.9 V in the saturation region, corresponding to an absolute specific on-resistance (RSP_ON) of 4.7 m9·cm2. From VCE=2.4 V to VCE= 5.8 V, the BJT has a differential RSP_ON of only 3.9 m9·cm2. The current gain is about 8.8 at Ic=5.3 A (869 A/cm2). This 4H-SiC BJT shows a V2/RSP_ON of 717 MW/cm2, which is the highest value reported to date for high-voltage and high-current 4H-SiC BJTs. A verylarge area 4H-SiC BJT with an active area of 11.3 mm2 is also demonstrated.


2021 ◽  
Author(s):  
Sara Sharifian Attar

The goal of this research was to develop a capability for the electrothermal modeling of electronic circuits. The objective of the thermal modeling process was to create a model that represents the thermal behavior of the physical system. The project focuses on electrothermal analysis at devices and chip level. A novel method to perform electrothermal analysis of integrated circuits based on the relaxation approach is proposed in this research. An interface program couples a circuit simulator and a thermal simulator. The developed simulator is capable of performing both steady state and transient analaysis at devices and chip level. The proposed method was applied to perform electrothermal analysis of Silicon Bipolar Junction Transistor (BJT) to predict the temperature distribution and the device performance in a circuit. Thermal nonlinearity due to temperature-dependent material parameters in the context of thermal modeling of the device and circuit has also been considered. The DC characteristics of the device were investigated. The obtained results indicate that the operating point of the device varies while the device reaches its junction temperature. The accuracy of the electrothermal simulator has been evaluated for steady state analysis. The experimental results of a BJT amplifier were compared to the simulator results of the similar circuit. The electrothermal simulation results of BJT amplifier circuit indicate a good agreement with the available experimental results in terms of power dissipation, collector current and base-emitter voltage. The performance of the electrothermal simulator has been evaluated for tansient analysis. A current mirror circuit using Si NPN BJTs was simulated. According to the electrical simulator, the output current follows the reference current immediately. Nonetheless, the electrothermal simulator results depict that the load current has delay to reach a constant value which is not the same as the reference current, due to the influence of thermal coupling and self heating. The obtained results are in agreement with the available results in literature.


2020 ◽  
pp. 144-148

Chaos synchronization of delayed quantum dot light emitting diode has been studied theortetically which are coupled via the unidirectional and bidirectional. at synchronization of chaotic, The dynamics is identical with delayed optical feedback for those coupling methods. Depending on the coupling parameters and delay time the system exhibits complete synchronization, . Under proper conditions, the receiver quantum dot light emitting diode can be satisfactorily synchronized with the transmitter quantum dot light emitting diode due to the optical feedback effect.


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