Patent ID: 7388403
Filing Date: 2008-06-17
Classification: H03K

Abstract:
1. A two-stage voltage level shifting module for a plurality of I/O devices having different bias voltages, comprising: a first stage voltage level shifting circuit; a first voltage source coupled to a first voltage input terminal of the first stage voltage level shifting circuit; a second voltage source having an voltage level higher than the voltage level of the first voltage source and being coupled to a second voltage input terminal of the first stage voltage level shifting circuit; a third voltage source having an voltage level higher than the voltage levels of both the first voltage source and the second voltage source; a first P-type MOSFET (metal-oxide-semiconductor field-effect transistor) having a source coupled to the third voltage source; a second P-type MOSFET having a source coupled to the third voltage source, a drain coupled to a gate of the first P-type MOSFET, and a gate coupled to a drain of the first P-type MOSFET; and a second stage voltage level shifting circuit comprising: