An LTspice simulation model of gamma-radiation effects and isothermal annealing in a voltage regulator with a lateral serial PNP transistor with round emitters

Vladimir Dj. Vukić

Abstract


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 isothermal 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. The influence of bias and load conditions were analysed with buildup of interface traps and the oxide-trapped charge, which affected the radiation and post-irradiation response of the serial power transistor.

Keywords


lateral PNP transistor; radiation effects; isothermal annealing; SPICE model; voltage regulator.

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References


J. Beaucour, T. Carribre, A. Gach, P. Poirot, Total dose effects on negative voltage regulator. IEEE T Nucl Sci 41 (1994) 2420-2426.

P.C. Adell, R.D. Schrimpf, W.T. Holman, J.L. Todd, S. Caveriviere, R.R. Cizmarik, K.F. Galloway, Total dose effects in a linear voltage regulator, IEEE T Nucl Sci 51 (2004) 3816-3821.

V. Ramachandran, B. Narasimham, D.M. Fleetwood, R.D. Schrimpf, W.T. Holman, A.F. Witulski, R.L. Pease, G.W. Dunham, J.E. Seiler, D.G. Platteter, Modeling total-dose effects for a low-dropout voltage regulator, IEEE T Nucl Sci 53 (2006) 3223-3231.

R.L. Pease, S. McClure, J. Gorelick, S.C. Witczak, Enhanced low-dose-rate sensitivity of a low-dropout voltage regulator, IEEE T Nucl Sci 45 (1998) 2571-2576.

N. Martinez, O. Gilard, G. Quadri, Total dose effects: A new approach to asses the impact of radiation on device reliability, IEEE T Nucl Sci 60 (2013) 2266-2271.

G.A. Rincon-Mora, Analog IC design with low-dropout regulators, McGrawHill Education (2014).

G.C. Messenger, M.S. Ash, The Effects of Radiation on Electronic Systems, Van Nostrand Reinhold (1992).

D.M. Schmidt, D.M. Fleetwood, R.D. Schrimpf, R.L. Pease, R.J. Graves, G.H. Johnson, K.E. Galloway, W.E. Combs, Comparison of ionizing-radiation-induced gain degradation in lateral, substrate and vertical PNP BJTs, IEEE T Nucl Sci 42 (1995) 1541-1549.

D.M. Schmidt, A. Wu, R.D. Schrimpf, D.M. Fleetwood, R.L. Pease, Modeling ionizing radiation induced gain degradation of the lateral PNP bipolar junction transistor, IEEE T Nucl Sci 43 (1996) 3032-3039.

R.M. Chavez, B.G. Rax, L.Z. Scheick, A.H. Johnston, Total ionizing dose effects in bipolar and BiCMOS devices, IEEE Radiation Effects Data Workshop (2005) 144-148.

K. Kruckmeyer, L. McGee, T. Trinh, J. Benedetto, Low dose rate test results of National Semiconductor’s ELDRS-free bipolar low dropout (LDO) regulator, LM2941 at dose rates of 1 and 10 mrad(Si)/s, IEEE Radiation Effects Data Workshop (2009) 59-64.

V. Vukić, P. Osmokrović, Total ionizing dose degradation of power bipolar integrated circuit, J Optoelectron Adv M 10 (2008) 219-228.

V. Vukić, P. Osmokrović, Impact of forward emitter current gain and geometry of PNP power transistors on radiation tolerance of voltage regulators, Nucl Technol Radiat 25 (2010) 179-185.

V.Dj. Vukić, P.V. Osmokrović, On-line monitoring of base current and forward emitter current gain of voltage regulator’s serial PNP transistor in radiation environment, Nucl Technol Radiat 27 (2012) 152-164.

V.Dj. Vukić, Minimum dropout voltage on a serial PNP transistor of a moderately loaded voltage regulator in a gamma radiation field, Nucl Technol Radiat 27 (2012) 333-340.

V.Dj. Vukić, P.V. Osmokrović, Power lateral PNP transistor operating with high current density in irradiated voltage regulator, Nucl Technol Radiat 28 (2013) 146-157.

V.Dj. Vukić, Computer simulation model for evaluation of radiation and post-irradiation effects in voltage regulator with vertical PNP power transistor, Inform MIDEM 48 (2018) 181-193.

H.J. Barnaby, B. Vermeire, M.J. Campola, Improved model for increased surface recombination current in irradiated bipolar junction transistors, IEEE T Nucl Sci 62 (2015) 1658-1664.

X. Li, J. Yang, H.J. Barnaby, K.F. Galloway, R.D. Schrimpf, D.M. Fleetwood, C. Liu, Dependence of ideality factor in lateral PNP transistors on surface carrier concentration, IEEE T Nucl Sci 64 (2017) 1549-1553.

A. Wu, R.D. Schrimpf, H.J. Barnaby, D.M. Fleetwood, R.L. Pease, S.L. Kosier, Radiation-induced gain degradation in lateral PNP BJTs with lightly and heavily doped emitters, IEEE T Nucl Sci 44 (1997) 1914-1921.

C.E. Barnes, D.M. Fleetwood, D.C. Shaw, P.S. Winokur, Post irradiation effects (PIE) in integrated circuits, IEEE T Nucl Sci 39 (1992) 328-341.

LM2940/LM2940C - Low dropout regulator, National Semiconductor (2003).

J.R. Murkland, J.S. Congdon, Lateral PNP Power Transistor, United States Patent 4417265, Nov. 22 (1983).

F.J. Franco, C. Palomar, J.G. Izquierdo, J.A. Agapito, SPICE simulations of single event transients in bipolar analog integrated circuits using public information and free opeen source tools, IEEE T Nucl Sci 62 (2015) 1625-1633.

LTSpice-Version 4.13q, Linear Technology Corporation (2012).

V.Dj. Vukić, Rapid and long-term gamma-radiation annealing in low-dropout voltage regulators, Nucl Technol Radiat 32 (2017) 155-165.

V.Dj. Vukić, P.V. Osmokrović, Failure of the negative voltage regulator in medium-photon-energy X radiation field, Microelectron Reliab 54 (2014) 79-89.

Standard.BJT, LT Wiki, Linear Technology Corporation (2012) http://ltwiki.org/?title=standard.bjt

D45H11 PNP Power Amplifier, OnSemiconductor (2013).

H.L. Hughes, J.M. Benedetto, Radiation effects and hardening of MOS technology: Devices and circuits, IEEE T Nucl Sci 50 (2003) 500-521.

T.R. Oldham, F.B. McLean, Total ionizing dose effects in MOS oxides and devices, IEEE T Nucl Sci 50 (2003) 483-499.

A.H. Johnston, R.T. Swimm, D.O. Thorbourn, P.C. Adell, B.G. Rax, Field dependence of charge yield in silicon dioxide, IEEE T Nucl Sci 61 (2014) 2818-2825.

T.R. Oldham, A.J. Lelis, H.E. Boesch, J.M. Benedetto, F.B. McLean, J.M. McGarrity, Post-irradiation effects in field-oxide isolation structures, IEEE T Nucl Sci 34 (1987) 1184-1189.




DOI: https://doi.org/10.33180/InfMIDEM2019.304

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