Patent ID: 6636402
Filing Date: 2003-10-21
Classification: H01L

Abstract:
A high voltage protection circuit in an integrated circuit comprising:a first transistor of a first conductivity type having a gate, a source, and a drain; and a second transistor of the first conductive type having a source coupled to the drain of the first transistor, a gate for receiving a supply voltage of the integrated circuit, and a drain for receiving a high voltage which is higher than the supply voltage, wherein the first transistor is formed in a first well of a second conductivity type and the second transistor is formed in a second well of the second conductivity type, the first and second wells being separate from one another, wherein the source of the second transistor is also coupled to the second well, and the source of the first transistor and the first well of the second conductivity type are coupled to a same reference voltage terminal.