Patent ID: 6177817
Filing Date: 2001-01-23
Classification: G05F,H03K

Abstract:
An off-chip driver circuit for integrated circuits comprising:a reference current amplifier circuit connected to an input voltage (Vcmn) for providing a reference current, and a reference current-voltage (Vbias2) on an output lead of the reference current amplifier circuit,an output driver circuit including a pull-up circuit stage having an input lead connected to the reference current amplifier circuit output lead and responsive to the reference current-voltage (Vbias2) to produce an output current on an output lead proportional to the reference current provided by the reference current amplifier, wherein the reference current amplifier includes first and second transistor devices connected in series to form a first current path and third and fourth transistor devices connected in series to form a second current path, wherein the reference current from the reference current amplifier flows in the first current path and the reference current has a level that is determined by the Beta of the second transistor of the first current path.