Patent ID: 7173482

Claim:
A complementary metal oxide semiconductor (CMOS) voltage regulator for low headroom applications comprising: a differential input common mode range amplifier; said differential input common mode range amplifier being formed by a plurality of CMOS transistors; said differential input common mode range amplifier including a first differential pair of CMOS transistors and a second differential pair of CMOS transistors; said first differential pair of CMOS transistors including a differential pair of P-channel field effect transistors (PFETs) and said second differential pair of CMOS transistors including a differential pair of N-channel field effect transistors (NFETs); a first differential input coupled to a first PFET of said differential pair of PFETs and a first NFET of said differential pair of NFETs; and a second differential input coupled to a second PFET of said differential pair of PFETs and a second NFET of said differential pair of NFETs; a source follower CMOS transistor coupled to an output of said differential input common mode range amplifier for providing an output of the CMOS voltage regulator; and a current source coupled to said differential input common mode range amplifier for maintaining a bias current through said differential input common mode range amplifier.