A pressure sensor includes a base having a high-pressure contact portion, and a diaphragm positioned over the base and having an external top surface opposite the base. The external top surface is defined within a closed perimeter and external side surfaces extend down from an entirety of the closed perimeter toward the base. A high-pressure contact portion of the diaphragm is aligned with and separated by a gap from the high-pressure contact portion of the base. A sensing element is coupled to the diaphragm and provides an output based on changes to the diaphragm. When a hydrostatic pressure load above a threshold value is applied to the entire external top surface and external side surfaces of the diaphragm, the hydrostatic pressure load causes the high-pressure contact portion of the diaphragm to contact the high-pressure contact portion of the base.