Patent ID: 6890066

Claim:
An improved ink ejector chip for an inkjet printhead, the ejector chip including a plurality of ejection devices for causing ink to be expelled from nozzles on the printhead toward a print medium, and circuitry on the chip connected to the ejection devices for controlling the activation of one or more of the ejection devices, the improvement comprising: at least one active device having power and ground connections, the active device including: a substrate having a resistivity and being devoid of an overlaying epitaxial layer, at least one dielectric layer disposed on the substrate, and at least one metallic layer disposed adjacent to the at least one dielectric layer and the substrate, a guard ring disposed on the substrate substantially surrounding the active device, wherein the guard ring tends to substantially prevent latch-up of the active device during operation of the ejection devices on the chip, a power lead electrically connected to the active device for providing power to the active device, and a ground lead electrically connected to the active device.