Power lateral pnp transistor operating with high current density in irradiated voltage regulator

Vukić, Vladimir Dj.; Osmokrović, P.

doi:10.2298/ntrp1302146v

Cited by 3 publications

(13 citation statements)

References 16 publications

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“…Minimum dropout voltage (for I OUT = 100 mA) was determined for a constant output current and the output voltage of 4.9 V [12,15]. For the second operation point, when I OUT was 400 mA, most of the performed measurement output voltages did not reach 4.9 V. Accordingly, results were recorded for the maximum available output voltage [16].…”

Section: Methodsmentioning

confidence: 99%

“…Therefore, according to the previous analysis, as well as the published data [12][13][14][15][16], it was assumed that the elements of the control circuit would have constant values, while the values of two power transistors (serial and driver PNP transistors) were changed for every control point. Comparison of the experimental and simulation data for the base current of the serial PNP power transistor, I B12 , are presented in figures 3 -6.…”

Section: Computer Simulationmentioning

confidence: 99%

“…In previous research, a detailed discussion was dedicated to analysis of the influence of the trapped charge type on the LM2940CT5 voltage regulator radiation re-sponse [16]. Taking into account that, above the base and emitter areas of the lateral power PNP transistor was highly contaminated isolation oxide, with an approximate thickness d ox = 500 nm [12], it was assumed that the oxide trapped charge would primarily affect this integrated circuit radiation response, while the interface trap concentrations would have secondary importance [16]. The primary reason for this supposition was the expectation that the concentration of the charge trapped in the oxide would be very high, with a proportion of N ot ~ d ox 2 [34,35] or even N ot ~ d ox 3 [34].…”

Section: Radiation Effectsmentioning

confidence: 99%

“…During the previous years, detailed research was conducted in order to define the topologies of cheap, commercial-off-the-shelf (COTS) low-dropout voltage regulators suitable for implementation in radiation environments instead of specially designed "rad-hard" components [12][13][14][15][16][17]. Among these candidates was a LM2940CT5 voltage regulator, an automotive circuit with lateral PNP power transistors with round emitters.…”

Section: Introductionmentioning

confidence: 99%

“…Among these candidates was a LM2940CT5 voltage regulator, an automotive circuit with lateral PNP power transistors with round emitters. Nevertheless, experimental results clearly indicated that these commercial integrated circuits had low radiation tolerance [12][13][14]16]. In the same period, examinations indicated that the specially designed, rad-hard LM2941W circuits exhibited high radiation tolerance [11].…”

Section: Introductionmentioning

confidence: 99%

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An LTspice Simulation Model of Gamma-radiation Effects and Annealing in a Voltage Regulator With a Lateral Serial PNP Transistor With Round Emitters

Vukić

2019

Informacije MIDEM

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The aim of this paper was to determine the reasons for a complex radiation response of the commercial-off-the-shelf LM2940CT5 low-dropout voltage regulator. Examination of this circuit in a gamma-radiation environment disqualified its use when operated with relatively high output currents, while its radiation tolerance was satisfactory when load current was approximately one-tenth (or lower) of the nominal value. In order to obtain a more thorough insight into the radiation response of this integrated circuit, a detailed SPICE model was developed. This model enabled mutual comparison of the influence of serial and driver PNP power transistor parameters: forward emitter current gain, knee current and emitter resistance. The serial lateral PNP power transistor with round emitters was identified as the weakest element that crucially affected the entire circuit radiation tolerance. The effects of gamma-radiation were examined for total doses up to 500 Gy followed by three sequences of annealing. Detailed characteristics of Beta(Ic) were procured for four different kinds of bias and load conditions during irradiation. The emitter resistance increase of the serial power transistor was a primary reason for the low radiation tolerance of the entire voltage regulator; it was much more influential than the perceived decline of the PNP power transistor forward emitter current gain.

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Section: Methodsmentioning

confidence: 99%

Section: Computer Simulationmentioning

confidence: 99%

Section: Radiation Effectsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

An LTspice Simulation Model of Gamma-radiation Effects and Annealing in a Voltage Regulator With a Lateral Serial PNP Transistor With Round Emitters

Vukić

2019

Informacije MIDEM

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Rapid and long-term gamma-radiation annealing in low-dropout voltage regulators

Vukić

2017

NUCL TECH RAD PROT

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Sam ples of four types of low-drop out volt age reg u la tors, with both se rial pnp and npn transis tors, were ex am ined in room-tem per a ture iso ther mal gamma ra di a tion an neal ing. Af ter un in ter rupted ex po sure to a to tal ion is ing dose of 500 Gy, bi ased and loaded volt age reg u lators were ex am ined in room-tem per a ture an neal ing within the first 30 min utes af ter the expo sure. Be side the on-line mea sure ment of out put volt age and qui es cent cur rent dur ing the thirty-min ute pe riod im me di ately af ter ir ra di a tion, also re sults were pro cured af ter 10-year room-tem per a ture spon ta ne ous re cov ery. Data ob tained dur ing the ir ra di a tion and rapid anneal ing were fit ted with lin ear, ex po nen tial, and power-law re gres sion func tions. A sim ple pro ce dure was pro posed, based on the qui es cent cur rent an neal ing fac tor, for the quick es tima tion of the in te grated volt age reg u la tor's ra di a tion sen si tiv ity dur ing the post-ir ra di a tion iso ther mal an neal ing. In or der to es ti mate the cir cuit's ra di a tion sen si tiv ity, im me di ately af ter ir ra di a tion, tested de vices have to be left in the same op er at ing con di tions as dur ing the ex posure. If a clear trend of the qui es cent cur rent re cov ery can be ob served, fur ther ex am i na tions have to be im ple mented to es ti mate if a cir cuit is ac cept ably ra di a tion-tol er ant. If no re cov ery trend can be ob served within the first hour af ter ir ra di a tion, or even fur ther deg ra da tion is no ticed, then the ex am ined volt age reg u la tor is a ra di a tion-sen si tive de vice and can not be used in ra di a tion en vi ron ments. The de scribed pro ce dure is based on the mac ro scopic ef fects of the ra di a tion-in duced charge-trap ping in field ox ides and in ter faces. Key words: volt age reg u la tor, gamma ra di a tion, qui es cent cur rent, an neal ing fac tor, iso ther mal an neal ing, post-ir ra di a tion ef fect, re gres sion anal y sis V. Dj. Vuki}.: Rapid and Long-Term Gamma-Ra di a tion An neal ing in ...

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Annealing influence on recovery of electrically stressed power vertical double-diffused metal oxide semiconductor transistors

Djorić-Veljković

Manić

Davidović

et al. 2015

Jpn. J. Appl. Phys.

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The effect of annealing on the recovery of electrically stressed power vertical double-diffused metal oxide semiconductor (VDMOS) transistors has been investigated. Behaviors of device threshold voltage and channel carrier mobility have been analyzed in terms of underlying changes in the densities of gate oxide charges and interface traps. The mechanisms responsible for the above-mentioned changes during the recovery of stressed devices have been analyzed as well. The annealing resulted in achieving stable threshold voltage and mobility, but did not ensure full recovery, as part of the stress-induced degradation remained permanent and could not be annealed. Namely, the annealing was found to enhance the neutralization of stress-induced oxide charges and the passivation of stress-induced interface traps, while the stability upon its completion resulted from the significantly decreased density of gate oxide charges and the possible balance between the processes of trap passivation and creation at the SiO 2 -Si interface.

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Power lateral pnp transistor operating with high current density in irradiated voltage regulator

Cited by 3 publications

References 16 publications

An LTspice Simulation Model of Gamma-radiation Effects and Annealing in a Voltage Regulator With a Lateral Serial PNP Transistor With Round Emitters

An LTspice Simulation Model of Gamma-radiation Effects and Annealing in a Voltage Regulator With a Lateral Serial PNP Transistor With Round Emitters

Rapid and long-term gamma-radiation annealing in low-dropout voltage regulators

Annealing influence on recovery of electrically stressed power vertical double-diffused metal oxide semiconductor transistors

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