US 12,107,583 B1
Total ionizing dose shutdown system and method
David A. Grant, Dallas, TX (US); Mark Hamlyn, Murphy, TX (US); and Kyle Schulmeyer, Murphy, TX (US)
Assigned to Apogee Semiconductor, Inc., Plano, TX (US)
Filed by Apogee Semiconductor, Inc., Plano, TX (US)
Filed on Apr. 4, 2024, as Appl. No. 18/627,080.
Int. Cl. H03K 5/1252 (2006.01); H03K 5/08 (2006.01); H03K 5/24 (2006.01)
CPC H03K 5/1252 (2013.01) [H03K 5/082 (2013.01); H03K 5/2472 (2013.01)] 30 Claims
OG exemplary drawing
 
1. A total ionizing dose (TID) shutdown system comprising:
a plurality of sensing circuits, each comprising
at least one TID sensor that produces a TID signal that changes monotonically with increasing total ionizing dose,
a reference producing a reference signal that corresponds to a dose at a predetermined TID level,
a comparator having an input connected to the TID signal and an input connected to the reference signal, and producing a signal at a comparator output that is active when the TID signal has a value relative to the reference signal that corresponds to a dose exceeding the predetermined TID level, and
a latch having an input connected to the comparator output and producing an overexpose signal at a latch output;
at least one controller configured to operate each sensing circuit in an integrate phase during which a bias voltage is applied to the TID sensor and a measure phase during which the TID sensor generates the TID signal, and to provide a signal to the latch to command the latch output to hold the overexpose signal;
at least one disagreement detector connected to the latch outputs and configured to generate a disagree signal that is active when the overexpose signals do not agree; and
a disable circuit connected to the latch outputs and configured to generate at least one disable signal that is active when a minimum number of the overexpose signals agree indicating a dose above the predetermined TID level.