Patent ID: 7652523

Claim:
A current mirror circuit, comprising: a. a reference current source, having an output, that generates a reference current; b. a reference transistor, having a first node having a first node voltage that is coupled to the output of the reference current source, a gate that is coupled to the first node, a second node coupled to a common voltage and a body; c. at least one mirror transistor, having a gate coupled to the first node, a source, a drain and a body; and d. a ratioed body bias feedback unit, responsive to the first node voltage, that generates a body bias voltage coupled to the body of the reference transistor and the body of the at least one mirror transistor, the ratioed body bias feedback unit configured to adjust the body bias voltage in relationship to the common voltage so that the reference transistor and the at least one mirror transistor each have a threshold voltage within a predefined range, the ratioed body bias feedback unit including a gate bias input that is electrically coupled to the first node; and a feedback circuit that is responsive to the gate bias input and that generates the body bias voltage, wherein the feedback circuit includes: i. a first n-type transistor having a drain coupled to the common voltage, a source, a body, and a gate that is coupled to the reference transistor gate; ii. a first p-type transistor having a source coupled to a voltage supply, a drain coupled to the source of the first n-type transistor, a body coupled to the voltage supply and a gate coupled to the source of the first n-type transistor; iii. a second n-type transistor having a drain coupled to the common voltage, a source coupled to the body of the first n-type transistor, a body coupled to the body of the first n-type transistor and a gate coupled to the body of the first n-type transistor; and iv. a second p-type transistor having a drain coupled to the body of the first n-type transistor, a source coupled to the voltage supply, a body coupled to the voltage supply and a gate coupled to the source of the first n-type transistor.