Patent ID: 8648582

Claim:
A programmable low dropout linear regulator using a reference voltage to convert an input voltage into a regulated voltage according to a first control signal, the programmable low dropout linear regulator comprising: an operational amplifier having a negative input coupled to receive the reference voltage; a first transistor having a gate coupled to an output terminal of the operational amplifier and a first source/drain coupled to an output terminal of the regulated voltage; a first impedance coupled between a positive input of the operational amplifier and the output terminal of the regulated voltage; and a second impedance coupled between the positive input of the operational amplifier and a ground; wherein the second impedance is consisting of a second transistor and a third transistor, the second transistor has a gate coupled to receive the first control signal, a first source/drain of the second transistor is directly coupled to the positive input of the operational amplifier, a first source/drain of the third transistor is directly coupled to a second source/drain of the second transistor, and a second source/drain of the third transistor is directly coupled to the ground; wherein the first impedance is consisting of a fourth transistor and a fifth transistor, the fourth transistor has a gate coupled to receive a second control signal, a first source/drain of the fourth transistor is directly coupled to the output terminal of the regulated voltage, the fifth transistor has a first source/drain directly coupled to a second source/drain of the fourth transistor and a second source/drain directly coupled to the positive input of the operational amplifier.