Integrated device having GDT and MOV functionalities. In some embodiments, an electrical device can include a first layer and a second layer joined with an interface, with each having an outer surface and an inner surface, such that the inner surfaces of the first and second layers define a sealed chamber therebetween. The electrical device can further include an outer electrode implemented on the outer surface of each of the first and second layers, and an inner electrode implemented on the inner surface of each of the first and second layers. The first layer can include a metal oxide material such that the first outer electrode, the first layer, and the first inner electrode provide a metal oxide varistor (MOV) functionality, and the first inner electrode, the second inner electrode, and the sealed chamber provide a gas discharge tube (GDT) functionality.

Glass sealed gas discharge tubes. In some embodiments, a gas discharge tube (GDT) can include an insulator substrate having first and second sides and defining an opening. The GDT can further include a first electrode implemented to cover the opening on the first side of the insulator substrate, and a second electrode implemented to cover the opening on the second side of the insulator substrate. The GDT can further include a first glass seal implemented between the first electrode and the first side of the insulator substrate, and a second glass seal implemented between the second electrode and the second side of the insulator substrate, such that the first and second glass seals provide a hermetic seal for a chamber defined by the opening and the first and second electrodes.

Glass sealed gas discharge tubes. In some embodiments, a gas discharge tube (GDT) can include an insulator substrate having first and second sides and defining an opening. The GDT can further include a first electrode implemented to cover the opening on the first side of the insulator substrate, and a second electrode implemented to cover the opening on the second side of the insulator substrate. The GDT can further include a first glass seal implemented between the first electrode and the first side of the insulator substrate, and a second glass seal implemented between the second electrode and the second side of the insulator substrate, such that the first and second glass seals provide a hermetic seal for a chamber defined by the opening and the first and second electrodes.