Study of characteristics of n-p-n type bipolar power transistor in small-sized metalpolymeric package type SOT-89

In this study the input, output and current gain characteristics of silicon n-p-n type medium power bipolar junction transistors KT242A91 made by the "GRUPPA KREMNY EL" in modern small-sized metalpolymeric package type (SOT-89) have been obtained. The SPICE model that allows simulating realistic transistor behaviour of n-p-n type transistor KT242A91 has been proposed. It is shown that established experimental characteristics for KT242A91 transistor correspond to similar transistor’s type characteristics.

Ultra-High Sensitivity MEMS Pressure Sensor Utilizing Bipolar Junction Transistor for -1…+1 kPa

The theoretical model and experimental characteristics of ultra-high sensitivity MEMS pressure sensor chip for the range of -1...+1 kPa utilizing a novel electrical circuit are presented. The electrical circuit uses piezosensitive differential amplifier with negative feedback loop (PDA-NFL) based on two bipolar-junction transistors (BJT). The BJT has a vertical structure of n-p-n type (V-NPN) formed on a non-deformable chip area. The circuit contains eight piezoresistors located on a profiled membrane in the areas of maximum mechanical stresses. The circuit design provides a balance between high pressure sensitivity (S = 44.9 mV/V/kPa) and fairly low temperature dependence of zero output signal (TCZ = 0.094% FS/°C). Additionally, high membrane burst pressure of P = 550 kPa was reached.

Ultra-High Sensitivity MEMS Pressure Sensor Utilizing Bipolar Junction Transistor for -1…+1 kPa

The theoretical model and experimental characteristics of ultra-high sensitivity MEMS pressure sensor chip for the range of -1...+1 kPa utilizing a novel electrical circuit are presented. The electrical circuit uses piezosensitive differential amplifier with negative feedback loop (PDA-NFL) based on two bipolar-junction transistors (BJT). The BJT has a vertical structure of n-p-n type (V-NPN) formed on a non-deformable chip area. The circuit contains eight piezoresistors located on a profiled membrane in the areas of maximum mechanical stresses. The circuit design provides a balance between high pressure sensitivity (S = 44.9 mV/V/kPa) and fairly low temperature dependence of zero output signal (TCZ = 0.094% FS/°C). Additionally, high membrane burst pressure of P = 550 kPa was reached.

Ultra-High Sensitivity MEMS Pressure Sensor Utilizing Bipolar Junction Transistor for -1…+1 kPa

The theoretical model and experimental characteristics of ultra-high sensitivity MEMS pressure sensor chip for 1 kPa utilizing a novel electrical circuit are presented. The electrical circuit uses piezosensitive differential amplifier with negative feedback loop (PDA-NFL) based on two bipolar-junction transistors (BJT). The BJT has a vertical structure of n-p-n type (V-NPN) formed on a non-deformable chip area. The circuit contains eight piezoresistors located on a profiled membrane in the areas of maximum mechanical stresses. The circuit design provides a balance between high pressure sensitivity (S =44.9 mV/V/kPa) and fairly low temperature coefficient of zero signal (TCZ = 0.094% FS/°C). Additionally, high membrane burst pressure of P = 550 kPa was reached.

Effect of Gamma Radiation on Characteristic of bipolar junction Transistors (BJTs )

This paper describes the effects of 60Cogamma radiation hardness of characteristic and parameters of Bipolar Junction Transistors in order to analyze the performance changes of the individual devices used in nuclear field. Bipolar Junction Transistor (BJT) of the type (BC-301) (npn) silicon, Transistor was irradiated by gamma radiation using 60Cosource at different doses (1, 2, 3, 4, and 5) KGy. The characteristics and parameter of Bipolar Junction Transistor was studied before and after irradiated by using Transistor Characteristics Apparatus with regulated power supplies. Obtained result showed that, the saturation voltage VCE(sat) of Bipolar Junction Transistor decreased because of the gain degradation of the transistor and increased silicon resistivity, Another parameter of a bipolar junction transistor affected by ionizing radiation is a collector-base leakage current, a strong increase of the current is caused by the build-up charge near the junction.

Thermal behavior characterization for MOSFETs and BJTs in hazardous locations

This paper shows a numerical polynomial approach to the topic of how bipolar junction transistors (BJT) and field effect transistors (FET) can be safe or unsafe when operating in explosive atmospheres. The most used transistors have been analyzed thermographically, working in a controlled environment, to characterize their thermal behavior. The target is to prevent the transistor from creating conditions that achieve the minimum activation energy for combustible vapors, dusts, or fibers/flyings. We have brought the transistors to their nominal values, specified by working currents and voltages, and confirmed that the effect of heat dissipation in a BJT is non-linear and much greater than in a MOSFET. We have experimentally found a thermal difference of more than 200ºC of overheating of a common BJT compared to a MOSFET with similar load in fixed polarization. We found temperatures above 300ºC in BJTs operating within their nominal ranges and conditions, when the accepted “safe” temperature is not supposed to exceed 200ºC in any case. Through a performance-based analysis focused on temperature, our research suggests that equipment with BJT technologies should not be implemented in certain areas of classified locations or explosive zones; so MOSFET technologies are preferable

A New Low Cost Current Measurement Circuit with Temperature Compensation

The electrical characterization of semiconductors devices, when submitted to ionizing radiation should be done in a large range of currents; however, the instrumentation with this ability is very expensive. This work proposes a low-cost circuit using commercial off-the-shelf components (COTS) that enables the measurement of electrical currents in the order of pA range. The circuit presents an output current that is an amplified version of the current to be measured, using the exponential relationship between currents and voltages in Bipolar Junction Transistors (BJTs) and Metal Oxide Silicon Field Effect Transistors (MOSFETs) when operating in the weak inversion region. Furthermore, a block was introduced in order to compensate the gain’s temperature dependence. The results showed that the operating range for the current that will be measured was more than seven decades using BJTs and five decades by using MOSFETs with a high linearity. The circuit version using MOSFETs was able to measure currents as low as 100 fA. The current gain has also good linearity for over five decades. This circuit has a stable behavior for the range of 20 °C to 40 °C, because of the temperature compensation block.

Investigation of Bipolar Degradation of 1.2 kV BJTs under Different Current and Temperature Conditions

Bipolar silicon carbide devices are attractive for high power applications offering high voltage devices with low on-state voltages due to plasma flooding. Unfortunately, these devices suffer from bipolar degradation, which causes a significant degradation of the on-state voltage. To explore the generation of stacking faults, which cause the degradation, the impact of the current density and temperature on bipolar degradation is investigated in this work. The analysis is done by stressing the base-collector diode of 1.2 kV bipolar junction transistors (BJTs) as well as the BJTs in common-emitter mode operation with different current densities at different temperatures.