NTE7172SM SOIC−8 surface mount package
 
The NTE7172 and NTE7172SM are overvoltage protection circuits that protect sensitive electronic circuitry from overvoltage transients or regulator failures when used in conjunction with an external “crowbar” SCR. These devices sense the overvoltage condition and quickly “crowbars” or short circuts the supply, forcing the supply into current limiting or opening the fuse or circuit breaker. The protection voltage threshold is adjustable and can be programmed for minimum duration of overvoltage condition before tripping, thus supplying noise immunity. The NTE7172 and NTE7172SM are essentially a “two terminal” system and, therefore both can be used with either positive or negative supplies.
 
 
 
Full spec sheet:
https://www.nteinc.com/specs/7100to7199/pdf/nte7172_sm.pdf