Honeywell International Inc.
SINGLE EVENT LATCH-UP PROTECTION FOR FAULT CURRENT RESIDING INSIDE THE NORMAL OPERATING CURRENT RANGE

Abstract:

Embodiments of a single event latch-up (SEL) protection circuit are provided, including: a first circuitry block coupled to a source of an input voltage a load, and digitally controlling a first switch; the first switch generates a load and senses an instantaneous load current iLoad. A second circuitry block is configured to generate an average iLoad and generate single event latch-up triggers (i.e., SEL fault detection) as a function of at least a comparison of the inst_iLoad and average iLoad; wherein this first circuitry block contains the analog based SET filtering needed to reduce false SEL triggers. A supervisor module generates on/off commands for the first switch, responsive to receiving the SEL detection in excess of a pre-programmed delay to provide the final SET filtering to prevent false SEL triggers. The first circuitry block removes the load voltage at N1 upon receiving an off command from the supervisor module.