IEEE TRANSACTIONS ON ELECTRON DEVICES AcKn IR Electron current incident on an electron-voltaic converte G.B. Shoop participated in the development of the I,= Current through the load of an electron voltaic the ac assembly of the batteries. J. Scott -Monck made the allium arsenide diodes and some of the silicon diodes. I The self-absorption limited electron current paport,who first conceived of this method of energy con- Io= Reverse saturation current of a diode. ss of a E. F. Pasierb, Jr, made the later silicon diodes. R. c. which would be emitted from the surface of a Hand designed the atomic battery assembly. P. Rap radioactive layer of semi-infinite thickne version, has provided helpful discussion 。 Short-circuit current of an electron-voltaic con- verter TABLE OF SYMBOLS Boltzmann's constant L. Diffusion length of electrons A, A'= Parameters used to describe the rate of de- L, Diffusion length of holes radation of semiconductors under electron ir- =q/ T. ao= Approximate self-absorption coefficient of Pm l47 "max Eleetron-voltaic conversion efficiency radiation q beta rays in cm tu= Radioisotope half-life. a/p Approximate absorption coefficient of Pm47beta T= Minority carrier lifetime rays in em /gm Minority carrier lifetime before electron ir- B Empirical constant to describe current voltage radiation relationship of a diode. Vmax Voltage across an electron-voltaic converter EB- Energy of an emitted electron under open circuit conditions EBsx Average energy of betas from a radioisotope. Vmp Voltage across an electron-voltaic converter at EBm Maximum energy of betas from a radioisotope a load which gives maximum power E. Energy gap of a semiconductor. Ionization energy required to generate and col- G Specific activity of a radioisotope in curies/gm lect an electron-hole pair in a diode. Analysis and Characterization of P-N Junction Diode Switching H. J. KUNOT, MEMBER, IEEE Summary--A new charge control model of a p-n junction diode Ⅰ NTRODUCTION is introduced in which the reverse current ig as well as the forward current IF are related to the charge Q stored in the base region by HE SWITCHING TIME of a semiconductor diode time constants Tg and Tp, respectively. The se switching is of great importance in computer circuit design transient is analyzed for normal switching operation where a con- Recently, in particular, development of very high exist, anrtent phase(storage phase )and a decaying current phase speed switching transistors made the switching time of current phase diodes much more significant than ever before. The switch equ ing time analysis of diodes have been carried out by some expressed in terms of measurable device para authors [1[8]. However, the switching tim he equations external circuit variables Ip and Ig; and an derived by most of the authors in the past, [1]-[41,[71, eter R. The proposed model is applicable to action diodes of [8), are expressed in terms of parameters which are ex- any type tremely difficult to measure and not practical for charac- ported. It is shown that the experimental results are in very good terizing the diode switching. It is, therefore, desirable for ent with the practical circuit design purposes to find new ways of characterizing the diode switching in terms of parameters s Received June 17. 1963 which can be measured simply 1968. Portions of this pa CON Con- In this paper the reverse switching transient is analyzed August, ational Cash Register Company, Electronics Division, Har and new diode switching time equations are derived thorne, calif. relating the reverse current ig as well as the forward Authorized licensed use limited to: IEEE Xplore. Downloaded on December 15, 2008 at 03 47 from IEEE Xplore. Restrictions applyIEEE TRANSACTIONS ON ELECTRON DEVICES January ACKNOWLEDGMENT I, = Electron curent incident on an electron-voltaic 6. B. Shoop participated in the development of the source deposition technique and performed the actual assembly of the batteries. J. Scott-Monck made the gallium arsenide diodes and some of the silicon diodes. E. F. Pasierb, Jr., made the later silicon diodes. R. C. Hand designed the atomic battery assembly. P. Rap￾paport, who first conceived of this method of energy con￾version, has provided helpful discussion. TABLE OF SYMBOLS Parameters used to describe the rate of de￾gradation of semiconductors under electron ir￾radiation. Approximate self-absorption coefficient of Pm14? beta rays in cm-l. Approximate absorption coefficient oiPm147 beta rays in cm2/gm. Empirical constant to describe current voltage relationship of a diode. Energy of an emitted electron. Average energy of betas from a radioisotope. Maximum energy of betas from a radioisotope. Energy gap of a semiconductor. Specific activity of a radioisotope in curies/gm. converter. = Current through the load of an electron voltaic converter. = The self-absorption limited electron current which would be emitted from the surface of a radioactive layer of semi-infinite thickness. = Reverse saturation current of a diode. = Short-circuit current of an electron-voltaic con- = Boltzrnann’s constant. = Diffusion length of electrons. = Diffusion length of holes. = q/kT. = Electron-voltaic conversion efficiency. = Electronic charge. = Radioisotope half-life. = Minority carrier lifetime. = Minority carrier lifetime before electron ir- = Voltage across an electron-voltaic converter = Voltage across an electron-voltaic converter at = Ionization energy required to generate and col￾verter. radiation. under open circuit conditions. a load which gives maximum power. lect an electron-hole pair in a diode. Analysis and Characterization of P-N Junction Diode Switching* a. J. KUNOt, MEMBER, IEEE Summary-A new charge control model of a p-n junction diode is introduced in which the reverse current iR as well as the forward current Zp are related to the charge Q stored in the base region by time constants 73 and T~, respectively. The reverse switching transient is analyzed for normal switching operation where a con￾stant current phase (storage phase) and a decaying current phase exist, and for overdriven switching operation where no constant current phase exists. New switching time equations are derived. The equations are expressed in terms of measurable device parameters Tp, TR, and Cj; external circuit variables ZF and IR; and an external circuit param￾eter R. The proposed model is applicable to p-n junction diodes of any type. Experimental results using various types of diodes are also re￾ported. It is shown that the experimental results are in very good agreement with the theory. * Received June 17, 1963; revised manuscript received August 20, 1963. Portions of this paper were presented at the WESCON Con￾vention, San Francisco, Calif., August, 1963. t National Cash Register Company, Electronics Division, Haw￾thorne, Calif. INTRODUCTION HE SWITCHING TIME of a semiconductor diode is of great importance in computer circuit design. Recently, in particular, development of very high speed switching transistors made the switching time of diodes much more significant than ever before. The switch￾ing time analysis of diodes have been carried out by some authors [1]-[8]. However, the switching time equations derived by most of the authors in the past, [I]-[4], [7], [8], are expressed in terms of parameters which are ex￾tremely difficult to measure and not practical for charac￾terizing the diode switching. It is, therefore, desirable for practical circuit design purposes to find new ways of characterizing the diode switching in terms of parameters which can be measured simply. In this paper, the reverse switching transient is analyzed and new diode switching time equations are derived by relating the reverse current iE as well as the forward Authorized licensed use limited to: IEEE Xplore. Downloaded on December 15, 2008 at 03:47 from IEEE Xplore. Restrictions apply