| dc.description.abstract | The growing demand for commercial off the shelf (COTS) electronic components in radiation
environments has driven the need for researching the total ionizing dose (TID) degradation of these components.
Most relevant systems require regulated DC voltages, often supplied by DC/DC switching converters. As
technology scales, desired converters are increasingly integrated onto a single die. As the power regulation circuitry
of these switching converters has become more compact, the ability to perform measurements on them has become
more difficult. Additionally, although the TID response of small-signal parameters for linear regulators – another
type of DC/DC converter – has been examined, previous work on the response of switching converters has focused
only on large-signal parametric shifts of converters built from discrete components. Small-signal parameters, such as
the loop gain, provide valuable information about the stability and disturbance response of a feedback circuit, such
as a DC/DC converter. This work examines the effects of TID on both large- and small-signal parameters of an
integrated, COTS, buck converter, a common type of switching converter, and it addresses the challenges of
performing loop gain measurements on an integrated chip. It is shown that the tested converter is surprisingly
radiation tolerant to moderate dose, experiencing only minor shifts in the loop gain which correspond to minor shifts
in the output voltage; however, it is prone to complete failure at a dose of tens of krads (Si). It is also shown that
variations in the turn-on voltage do not follow a clear trend. | |
