Patent ID: 6949972
Filing Date: 2005-09-27
Classification: G05F

Abstract:
1. A circuit for outputting a sink current, comprising: a first current mirror that includes a power transistor and a sense transistor, wherein the power transistor is arranged such that a drain current of the power transistor is substantially greater than a drain current of the sense transistor; a feedback circuit that is coupled to the first current mirror and arranged such that a drain voltage for the sense transistor is relatively equivalent to a drain voltage for the power transistor; a follower circuit that is coupled to the first current mirror and arranged such that an output terminal of the follower circuit is coupled to a gate of the power transistor and a gate of the sense transistor, wherein the follower circuit enables the drain current of the power transistor and the drain current of the sense transistor to substantially reach equilibrium in a relatively short period of time if an input signal is asserted; and a current sinking circuit that is arranged such that the outputted sink current is substantially turned off in a relatively short period of time if the input signal is de-asserted, wherein the current sinking current is coupled to the gate of the power transistor and the gate of the sense transistor.