Patent ID: 7755419

Claim:
An integrated circuit device, comprising: a self-biased reference circuit that provides a reference value to the integrated circuit device, the reference circuit being disposed between a first power supply node and a second power supply node that receives a power supply voltage of about zero volts, the reference circuit including a first current mirror coupled to the first power supply node and comprising a pair of first transistors of a first conductivity type; and a second current mirror coupled between the first current mirror and the second power supply node and comprising a pair of second transistors of a second conductivity type, the pair of second transistors having different threshold voltage values from one another; a start-up circuit comprising; a start-up current path coupled between the first power supply node and the second power supply node, the start-up current path comprising: a reference current transistor having a threshold voltage that is closer in magnitude to the power supply voltage than the first transistors and the second transistors and is in a range of about −100 millivolts to about +100 millivolts, wherein the reference current transistor has its gate electrically coupled to its source; a current supply transistor coupled to the reference current transistor; and an activation device coupled between the first power supply node and the self-biased reference circuit that is enabled in response to a potential established by the reference current transistor, wherein a current drawn by the reference current transistor is compared to a current supplied by the current supply transistor to determine when the activation device is enabled.