Five new Apple patents have appeared at the US Patent & Trademark Office. Following is a summary of each.
Patent number 7,834,662 is for a level shifter with embedded logic and low minimum voltage. In one embodiment, a level shifter circuit may include a shift stage that also embeds transistors that implement a logic operation on two or more inputs to the level shifter. At least one of the inputs may be sourced from circuitry that is powered by a different power supply than the level shifter and circuitry that receives the level shifter output. Additionally, the level shifter includes one or more dummy transistors that match transistors the perform the logic operation, to improve symmetry of the level shifter circuit. In some embodiments, certain design and layout rules may be applied to the level shifter circuit to limit variation in the symmetry over various manufacturing variations. The inventors are Brian J. Campbell, Vincent R. von Kaenel, Naveen...| Read more »