NT & RP Journal
ON-LINE MONITORING OF BASE CURRENT AND FORWARD EMITTER CURRENT GAIN OF THE VOLTAGE REGULATOR'S SERIAL PNP TRANSISTOR IN A RADIATION ENVIRONMENT
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Vol. XXVII, No. 2, Pp. 95-197
June 2012
UDC 621.039+614.876:504.06
ISSN 1451-3994

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Pages: 152-164

Authors:
Vladimir Dj. VukiŠ, Predrag V. OsmokroviŠ

Abstract


A method of on-line monitoring of the low-dropout voltage regulator's operation in a radiation environment is developed in this paper. The method had to enable detection of the circuit's degradation during exploitation, without terminating its operation in an ionizing radiation field. Moreover, it had to enable automatic measurement and data collection, as well as the detection of any considerable degradation, well before the monitored voltage regulator's malfunction. The principal parameters of the voltage regulator's operation that were monitored were the serial pnp transistor's base current and the forward emitter current gain. These parameters were procured indirectly, from the data on the voltage regulator's load and quiescent currents. Since the internal consumption current in moderately and heavily loaded devices was used, the quiescent current of a negligibly loaded voltage regulator of the same type served as a reference. Results acquired by on-line monitoring demonstrated marked agreement with the results acquired from examinations of the voltage regulator's maximum output current and minimum dropout voltage in a radiation environment. The results were particularly consistent in tests with heavily loaded devices. Results obtained for moderately loaded voltage regulators and the risks accompanying the application of the presented method, were also analyzed.

Key words: forward emitter current gain, base current, pnp transistor, on-line monitoring, voltage regulator, quiescent current, gamma radiation

FULL PAPER IN PDF FORMAT (1,81 MB)

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