Patent ID: 11966247
Assignee: PSEMI CORPORATION
Field: Control (Instruments)
Classification: CPC G | IPC G

Claim 18:
19. A method for operating a cascode current mirror with low headroom voltage, the method comprising:
realizing an input leg of the cascode current mirror by series-connecting a common-source composite transistor with a first common-gate intrinsic transistor;
realizing an output leg of the cascode current mirror by series-connecting a first common-source transistor with a second common-gate intrinsic transistor; and
biasing gates of the first and second common-gate transistors with a voltage at an intermediate node that connects two series-connected transistors of the common-source composite transistor,
wherein
a ratio between a width and a length of each transistor of the two series-connected transistors is twice a ratio between a width and a length of any one of the first common-source transistor, the first common-gate intrinsic transistor, or the second common-gate intrinsic transistor, and
the common-source composite transistor comprises two series-connected transistors with gates directly connected to a gate node of the common-source composite transistor.